KicsterAsh is one of the few writers I've seen who can do completely in-character teen versions of the boys and their friends. Most (if not all) of her fics are set while the boys are 15/16, and they deal with some quite serious themes (lingering feelings of loss), while still managing to retain the endearing feel of the characters and their world. Well worth a read.
Seconded by Arctimon. Unlike other fics, personalities and quirks are kept intact while expanding on the universe of the show. Agreeing with Monoxide; well, well worth the read.
Thirded by Insano. The author does an awesome job of keeping the characters' personalities consistent while putting them in new situations. The following link is the author's biggest project of Pn F fics:The Seer.
Fourthed (if that's a word) by Cosmic Pickle. I was blown away at her epicness. Her fic The Things I Will Risk For You is amazing!
One of the worst writers I've seen. Her art isn't bad but her stories are NOTHING like the show. You will be hard pressed to find a single one that focuses on inventing. The B plot is almost always dropped entirely, Perry talks, and the characters are nothing like themselves. Almost every fic features Phineas, one of the happiest characters on TV, being sad and depressed from start to finish. Most of the stories usually focus on Phineas crying over the loss of his father Francis Flynn while treating Lawrence like a second class citizen. This goes against the spirit of the show and is occasionally accompanied by Ferb spending an entire fic sobbing over the loss of his mother. This doesn't happen just a few times either...most of the stories are this and there are a lot of them. This writer even reuses the exact same story for her original works but simply renames the characters. Francis Flynn is still Francis Flynn and Phineas Flynn is renamed Sparky Flynn. He has a step brother named Leo with blue hair. Sound familiar? When the stories aren't focusing on depression, they are focusing on a sickly amount of poorly done shipping. The worst fic she has written is "The Seer", which is 3 books long, over 100 chapters, and filled with constant filler. Most of her fictions share this problem in that they are too long and too much time is spent doing nothing.—Darkest Lord.
Although, most are really fair arguements, the reason why the fics don't focus much on inventing is because, it takes place during, when Phineas, Ferb and the others are in school. It's hard for them to do much inventing, in that time outside of weekends and holiday offs. Plus it's not fair for people to say !Teen Phineas and !Teen Ferb are out of character when was don't know WHAT Phineas and Ferb will be like as teenagers and adults. What I don't like about Kicsterash's fics however is how people hate Phineas/Ferb cause they're stepbothers yet find Phinbella's kid, Marie, and Ferbnessa kid, (stepcousins) together, perfectly OK, and free of sin. —Candycane14.
I have to admit,she's quite meh with me. She does write and draw beautifully and while I do agree cartoons sometimes need to balance comedy and drama,but...DANG! She depresses the hell out of me sometimes. Honestly,PAF is primarily an animated comedy,so she went too far in some prospects. I respect Francis Flynn as a fanon character,not a real character. She talks bout him in almost every single PAF pic being overly Anvilicious while doing it. I can't help but feel she's addressing a death of hers in PAF but I could never be sure. Today,I discovered that she's working on the hyped "Act your Age" character designs. When she got on board with the PAF crew,they made Francis a real character,meaning that Phineas' father officially died in a car accident in canon. You have no idea how painful it is for me to type this out. Not to mention her just taking him out of the series after his spirit always stitched into every single sob story not allowing everyone to draw him. The least you can do is allow people to keep the legacy going like you wrote about fifty times. I'll admit,she does know how to design the characters well in teenaged form but...I just feel iffy about her. A bit too depressing for me,but does have merits.I also think that the Seer is highly overrated.-cakeface33
Recommended by Ladyofthe Shield, Sols mainly writes Pn F when they're teenagers. Her stories are wacky and original, and she specializes in suspense. She writes no romance- though Isabella and other minor characters make appearances- and mainly focuses on the bond between Phineas and Ferb.
Stories focused on the family and the friendly relationships of the cast. Plot-focused stories or light day-in-the-life stories. Pretty much anything that isn't focused on romance.Evil Phineas by The Cartoon Fanatic 01
Synopsis: When Phineas is hit by Doofenshmirtz's reconstructed Turn-Everything-Evil-Inator, he becomes a villain out to conquer the world. Now, Ferb, Candace, Perry, Isabella, and the entire gang must find a way to save Phineas before it's too late. RESTARTED AFTER A HIATUS!
Synopsis: When Candace suffers from a really bad cold, Phineas and Ferb embark on inventing a cure for it. Meanwhile, Perry finds that Dr. Doofenshmirtz is making a machine to cure the illness that he thinks has struck Vanessa. Hilarity Ensues in both sub-plots.
Comments: This troper is quite amazed at how well the writer was able to take a Phineas and Ferb story concept and give it the kind of narration one would expect to see in a older-demographic novel, and yet at the same time still feel like an actual episode of the show.
Seconded by Arctimon. I could imagine the episode forming in my head when reading the story. Probably one of the best (if not the best) P&F fanfictions out there.
Synopsis: When she hears Drakken is up to no good in a place called Danville, Kim Possible, along with Ron, travels there to stop him, and meets a very creative pair of step-brothers, their incredibly hyper sister, and an odd ally.
Tags: Crossover, humor.
Comments: If you've ever wondered what would happen if Drakken & Doofenshmirtz teamed up or wanted to see Rufus & Perry work together, this is the fic for you. Everyone is in character and the Canon is adhered to. There are some things that are kind of slow (Phineas & Ferb's project, a detective business, never really goes anywhere). Could be considering Pandering to the Base, but still entertaining.
Synopsis: The story follows Irving in his day-to-day escapades with his brother and friends (the rest of P&F & co.).
Comments: You've probably heard of this one from around this very site. Regardless of what you think of Irving, you must admit two things:
This guy's good with characterizations, for ALL characters.
He can sure as heck make a joke. The main feel of the series is pretty well maintained through it all. It's never too serious, it's just a lot of fun. Plus, save for some minor proofing errors, it's a pretty easy read.
Synopsis: Doofenshmirtz attempts to adopt his younger self. Perry thinks this is a bad idea. No shipping.
Comments: I really liked this. Doofenshmirtz was appropriately idiotic, Perry seemed like himself, Gimmelschtump was just as horrible as ever. It was over all a bit sad, a bit funny, and a bit heartwarming. Recommended.
Synopsis: When Dr. D's family comes to visit Phineas and Ferb's, Vanessa and Candace team up to bust Phineas and Ferb's gift for Vanessa and Dr. D up to no good, as usual. but the worst part is that Perry must stop him...with his cover at stake!
Comments: It's a great story that takes all of the main parts of a regular episode puts them all together.
Synopsis: Ferb wakes up in the middle of the night after having a nightmare. To keep his mind of the bad dream, he re-calibrates his GPS so it will track family members. He ends up getting a signal from a girl named "Jessica G. Fletcher" that's only a few miles away from him....
Comments: There's a page for it. Anyway, this is well written with a very interesting plot and terrific story. Plus it proves that theory I had for years! Recommended!
Synopsis: When your humanity is taken from you... sometimes you have to take some strange steps to regain it.
Comments: A Perry-centric story that has a very interesting take on his origin, why a platypus is so humanlike, and how he met Dr. D. It really picks up after the first chapter, this reader was very impressed.
Synopsis: After Candace gets "busted," Phineas starts to feel bad for his sister, so he wants to help her, even if she is partly mad at him.
Comments: A Fix Fic for those who didn't like the ending of "Candace gets busted". Everyone's in character and the story is well written. There's drama and hurt/comfort in it. A good family story between Candace and her brothers(especially Phineas).
Synopsis: Vanessa's fights with her dad would probably last a lot longer if the guilt and remorse didn't go both ways. One-shot.
Comments: This is amazing. Commander catches the father-daughter dynamic of these two quite well, and makes the relationship they have pretty tearjerking. She also perfectly captures what goes on in any teen's mind when they return to a parent after an awful fight (not to mention the forgiveness/unconditional love on the parent's end).
Tags: Family, drama, hurt/comfort at the end. A word of warning: there is brief talk of miscarriage near the end.
Synopsis: How did Parallel Phineas and Ferb decide break the rules and transform into the anti-conformists who wore what they wanted and built extraordinary gadgets? How did First-dimension Phineas' dynamic personality affect Parallel Phineas? MISSING SCENE FIC.
Comments: I can't recommend this fic enough, it's a great look into what motivated the alternate Phineas and Ferb to rescue their sister from Alternate!Doofenshmirtz, while giving some background information of Alt!Doofenshmirtz's evil reign... though it can get a tad dark at times...
Synopsis: With summer ending, Phineas and Ferb are on a quest to prevent losing their friends, while Perry has to protect them and stop Dr. Doofenshmirtz and his new L.O.V.E.M.U.F.F.I.N. Old characters return, takes place after their journey into the 2nd dimension.
Comments: This story is great. I can really see this as a grand finale to the show. It's full of action, humor, romance and continuity nods. It even has a few songs the author wote, making it seem more like an actual Phineas and Ferb episode or movie. It does have a few typoes, but they are very few and far between.
While the story is good enough, it's *far* from great. It's choppy and while it could do well in a cartoon format, it's does not hold up well in a written story format. There also seems to have been a mix up around pages 10 and 11, repeating the same chapter. Than you get to 12, where it's suddenly jumped to a COMPLETELY different scene for no reason. The story has a lot of potential, but the whole thing just seems very half baked.
Synopsis: The sanest ones are the inmates! A charming alternate universe story about our beloved Phineas and Ferb cast...in a mental house. Jeremy is a doctor there and experiences their quirks and problems and creates a little family.
Comments: This is one of the best AU stories I have ever read. Each character retains their personality, even through a slew of personality and mental disorders alike. The writing is well-constructed; the dialogue is charming; and the absolute attention to detail and everyday life is fantastic. Well worth a read.
Synopsis: Perry is protective over his naive owners, especially since he almost lost them in the alternate dimension fiasco He never expected them to get put in harm's way ever again until someone kidnaps Phineas, leaving no name but lots of cruel intentions.
Comments: Lots of twists and turns, false leads, and exciting cliffhangers are scattered through this story. Everyone from the show is practically dragged into events at some point. Multiple searches for the missing boy are running simultaneously: the police and his parents, his friends, and by a very worried semi-aquatic egg-laying mammal of action. But even with all the worrying, dread, and multiple reveals that things are not as simple as hoped, there is still some familiar humor that crops up to keep things from becoming too dark. And the fact that Phineas has been kidnapped allows Ferb to be in the spotlight for a change.
Synopsis: 100-word drabbles, with single words of inspiration. Fluff and pairings galore. Rated T for safety.
Comment: A collection of short stories done by the author. Some of them are requested by readers. There are many short pieces that one can enjoy. Some of the drabbles are focused on romance, others on friendship, others that are just for fun and so on.
Synopsis: When Phineas and Candace's birth father returns, Candace sends him away. But with Phineas he won't take no for an answer. Once he's taken both Phineas and Ferb, can Candace and the other kids find them in time?
Comment: This story gripped this troper right from the first chapter, as things already were very intense and intriguing. It is a good theory on the Flynns' biological father, and William himself was very sinister. There is also more drama from the the boys' disappearance too.
Synopsis: When Phineas and Candace wake up on a Friday morning in each other's bodies, they must find a way to switch back before sun set because by sun set, the change becomes permanent, and they become each other forever. Can they switch back before it's too late?
Comment: This is a nice funny story involving a popular trope. It keeps everyone in character. It's a good read.
Synopsis: Isabella Garcia Shapiro never expected her life to change in an instant after her boyfriend Phineas has been kidnapped. Now, with the help of some old friends will Isabella find her lost boyfriend? Phinbella, Ferbnessa, pairings to come
While there is a fair bit of shipping in story, it's mostly light and the story focuses more on Isabella, Ferb and their friends' desperation to find Phineas. It's well written and worth the read.
Synopsis: Sometimes, we only see one side of a person, but no one is so simple as to be seen fully from one side. To get a full view, we need to see them in different settings and situations. Of course, some people are more complex than others, and so we need to see more. With Candace, well...let's say we'll definitely need more.
Comment: 50 drabbles all about Candace. Some are heartwarming, some are funny, and some are tearjerkers and all of them are in character.
Seconded by Shiny Aeon. These little slices-of-life really ring true for Candace. Well-done and memorable.
Synopsis: At the beginning of summer one of Doofensmirtz's -inators hits Candace and turns her into a mermaid whenever she is covered in water. She now has to go through several episodes of the series trying to controls her new form and abilities, learning to share secrets with others, and even learning Perry's double life in the process.
Comment: It's has interesting new takes on a lot of the episodes featured, including the 2nd dimension movie. There is a lot of great character development in this story, namely Candace and Perry after they learn each other secrets. There is now series of stories done by the author, including two crossovers with  and one with  and a few one-shots. All are well-written and enjoyable to read. It's great series of Candace fans.
Synopsis: Fifteen years in the future, Phineas Flynn returns to Danville for a high school reunion. There, he finds a romance that he thought would never be possible in his lifetime. But what will that bring from the forces that intend to destroy this spark of love, including a certain woman from his romantic past?
Synopsis: Ferb develops romantic feelings for Fireside Girl Gretchen (the one with the glasses) and asks Isabella for advice on how to tell it to her. He gets a nice surprise when he gets around to it.
Comments: The author of this story says that he felt that, since Phineas had Isabella, Ferb needed a girlfriend too, and Gretchen was the most logical choice. And I'd have to say he made a good choice; this story of his turned me into a Ferb/Gretchen shipper!
Pairing(s): Phineas/Isabella, with mentions of Ferb/Vanessa.
Synopsis: A collection of twenty-six oneshots that follow the Alphabet, the story chronicles the lives of twenty-three year old Phineas and Isabella as a couple.
Comments: A well written collection with proper grammar, descriptions and great characterizations, Alphabet Soup does a great job of exploring the relationship of Phineas and Isabella. It covers everything from fights and (Slight) angst to fluffy and romantic instances. That, and You'll learn what words like Jocose and Quixotic mean.
Alphabet Soup is great, but this troper would gladly recommend any of her four stories. The writing is beautiful, and her characterization is awesome. Hard to believe (as of this writing) she's only been writing for about a month. Her only problem seems to be a lack of confidence, which is a shame—because her stuff is really good.
Synopsis: Stacy has always been annoyed with Candace's obsession with Jeremy and busting, and she's always wish Candace would pay more attention to her. But maybe's there's a deeper reason then we thought...
Comments: Yes, this is slash. But bit's some of the most well written slash ever. Everyone is in charector mostly, and can totally see this in canon, if it had to deal with this subject. And most of all, it's adorable! Even Non Yuri Fans can get a kick out of it.
Synopsis: The story focus on the boys' relationship and how everyone reacts to it.
Comments: Also a slash fic and also one of the most well written slash stories in the Pn F fandom. It's almost close to the show. Everyone's in character and their reactions were very realistic and believable. Phineas and Ferb are actually portrayed as bisexual (something VERY rare in slash fandoms), and there's barely even any smut in this fic. The most recommended chapters to read are 'Gonna be all right', 'Shaking hands', 'Fate isn't good enough', and 'Time flies'.
Seconded by Blazichu. Even if you're wary of the slash, give it a shot— your faith will be rewarded. Mine certainly was.
Synopsis: What happened to the world counterparts after the movie?
Comments: Ever wonder what happened to The Resistance after Across the 2nd Dimension? Then read this fanfic. It includes romance, betrayal (especially when Alt. Phineas quits The Resistance and becomes evil after his parents are accidentally killed by a Resistance weapon and Alt. Candace doesn't seem to care about it), and a whole lot of action.
Synopsis: Baljeet agrees to go to Junior Prom with Wendy, and Buford is inexplicably furious.
Comments: The Bujeet ship is really lacking in good chapter fics, but this fanfic basically makes up for it. The characters and relationships are believable, the plot hasn't been dragged out over an obnoxious amount of chapters, and it's incredibly cute while also being quite serious. The end is a little wild, but it sort of adds to the experience of the story. It's definitely worth the read.
Synopsis: Phineas, Isabella, and Bajleet swap ages with Candace, Jeremy, and Stacy. Phineas and Isabella start realizing how much they mean to each other, as Candace recruits Jeremy and Stacy into a Big Idea of her own.
Comments: In addition to some excellent handling of Phineas and Isabella suddenly getting hit with teenage hormones, the Candace side of the story shows how similar she and Phineas can really be as she decides to help Jenny's food drive in a way that even Phineas and Ferb would be proud to call their own.
Synopsis: A series of stories when Phineas, Ferb and their friends are 15-16 years old featuring the above romantic pairings and the situations they get into (if you are interested in how most of the pairings started, check out more of Lowrider's stories).
Comments: This was a very fun and interesting story to read. The situations the characters get into are both good and bad, there are funny moments and the pairings work well (to the point that this troper got interested in reading the stories about other pairings he wasn't originally interested in). This troper particularly liked Adyson and Django's story arc, as their relationship has a lot going on, and the conclusion to their storyline is quite saddening. There is some mildish sexual content in it, so be warned if you don't like that stuff. Follows in the same timeline as A Day in the Life, above.
Pairings: Ferb/Vanessa, oblivious!Phineas/Isabella, Candace/Jeremy, hints of Django/Gretchen
Synopsis: Ferb is reminded of a Pleasure Garden his grandparents took him to in England, and convinces Phineas to build one as today's big idea. Vanessa stops by to visit due to a mysterious invitation she receives.
Comments: karly05 has written many stories covering Ferb and Vanessa's relationship, but this is the linchpin of the series. In addition to setting up Perry as a short turquoise matchmaker, it does an excellent job characterizing both the early beginnings of their relationship and the issues with Phineas and Isabella's at this stage. Other stories in the series are more strongly rated, but this one could easily be an episode of the series.
Synopsis: "Who am I? I'm what many a grown-up would call a "gifted young man". I have a knack for planning, assembling, and constructing. I have a platypus who means the world to me, and a stepbrother who means everything to me. My name is Ferb Fletcher. This is my story. I don't talk much, but ask me if I've been keeping secrets, and I'll probably lie."
Comments: This reads like a special episode of the show, something like Mission Marvel. Think of it like this: what if Phineas and Ferb did an hour-long special giving homage to 007? Part one complete, part two unfinished.
Stories that blend one universe with anotherThe Crossroads by Jaywings
Synopsis: When the Doctor visits a strange town to investigate a world-famous scientist whose experiments may sometimes be regarded as... questionable, the TARDIS vanishes and leaves him behind with no idea where it has gone or who might be behind its disappearance.
Synopsis: The Black Hole Army's been busy fighting the forces of Chaos in space for quite some time. However, it is not only time for this war to end, but also for Sturm to head back to a world that he visited to keep his end of a deal that he made in the past. The true identity of Phineas' father will also be revealed. This story is a Advance Wars/Phineas and Ferb/Warhammer 40k crossover.
"Mom! Phineas and Ferb are inspiring future generations of writers!"