The Mafia: Dan's plan to get revenge on Elise's parents involves convincing the police that her father is part of it, which leads to real Mafiosi trying to kill him. It's a lie, of course, but it turns out Elise's mother is secretly working for a rival Family.
Male Gaze: In "Technology", once Elise is put under mind control and gets into that chrome skin-tight suit, the camera doesn't hesitate to get as many shots of her from the rear as possible.
Married to the Job: Jeff the Burgerphile manager, to the point where he would rather lie about getting Dan's order wrong than admit to the mistake and blemish his otherwise perfect service record.
The androids. They may look human, but they're hard as a rock and surprisingly brittle.
Mind-Control Device: Barry Ditmer's plan in episode "Technology" is to create a long-range wireless mind control device to force people to buy his products. He also has a smaller short-range headband device that he uses to turn Elise into his minion.
Mugging the Monster: Every episode begins with someone messing around with Dan's life, thinking that he's just some crazy, misanthropic jerk. Dan quickly shows them that he's a determined, obsessive, occasionally intelligent, crazy, misanthropic jerk.
Nonstandard Character Design: In his first appearance, Imposter Dan looked like a really badly drawn Dan, making him really stand out. For his later appearance, minor tweaks were made to his design so he didn't look so out of place.
Noodle Implements: Dan's plan for destroying Chris "involves two Bengal tigers, an albino child, and five... no, six gallons of hummus." He hasn't worked out the details yet.
Noodle Incident: Dan's grandmother died at some point (offscreen). Since then, Dan has expressed his dislike of her and made mention of some unspecified unpleasantness which he does not regret.
No Kill Like Overkill: Dan got angry at a squirrel for an unspecified reason and was unable to find afterwards, so he decides to hijack some nuclear missiles and destroy all life on Earth to make sure that he kills the right squirrel. Elise stops him from going through with it though.
Averted. Dan even refuses to let Chris drive away from an imminent explosion until he puts on his belt.
Played straight in "Technology" when they get in a wreck and Dan is thrown through the windshield resulting in a Non Sequitur Thud.
Dan: Rainbows are nature's rainbows.
No Theme Tune: The beginning of the episodes tend to have something terrible happen to Dan, and then Dan screaming skyward about the episode's subject. There actually is an ending theme, but it's not heard on TV since, like nearly all networks, the Hub runs promos over the end credits.
Not Good with People: Dan is... a mild example of this. Not to say that he only somewhat hates humans, of course, but he appears to have a soft spot in his heart for cute fuzzy animals, such as Mr. Mumbles and the monkey in 'Common Cold'.
Dan and Elise on occasion, since Elise also has a pretty vindictive side.
In "The Dinosaur", Dan bonds with the dinosaur when he sees her enjoying television, eating burgers, and yelling angrily at people. Just like Dan. He can't bring himself to kill her after that and settles for sending her his car repair bill. She responds with a Skyward Scream. Just like Dan.
Imposter Dan may be nicer than the real Dan but "The Telemarketer" reveals that he's just as vengeful as Dan is.
Not-So-Imaginary Friend: Well, Not So Imaginary Enemy, but Chris and Elise are pretty sure Dan has lost his mind in "Dan".
Obfuscating Stupidity: The governor and his work release employee in "Stupidity". The governor is a British villain pretending to be an uneducated hick in order to bring down the education system in America while the employee is a government agent working undercover to stop him.
Once Killed a Man with a Noodle Implement: In "The Salvation Armed Forces", Dan tells his friend Chris that the bell ringer knows twelve ways to kill a man with a bell. Chris thinks about it, but can only come up with one.
One Dialogue, Two Conversations: In an argument with a pitcher, Dan can be heard ranting about how he didn't learn how to tie his shoes until he was twelve.
Only Friend: Chris is Dan's only friend. Ted is occasionally mentioned, but has yet to actually appear on the show, probably because Dan is usually mad at him.
Only One Name: Dan, although given that Chris' last name is Pearson, and named after one of the show's writers, it's quite probable that Dan's last name is Mandel, after his own namesake.
Only Sane Man: So far, Chris is the most normal of the cast aside from the fact that he's apparently a werebear or something. Dan really should rethink his habit of sticking his fingers in Chris's mouth.
Origins Episode: "Summer Camp", where Dan recounts to Elise how he and Chris met and how he embarked on his first revenge mission ever against the corrupt camp director, Mr. Tedesco.
Our Werewolves Are Different: The Wolfman in the eponymous episode doesn't seem to know about being a werewolf, as evidenced by wondering aloud who shot him in the butt with a silver arrow. The Wolfman itself is a general troublemaker, but isn't seen doing anything worse than damaging cars.
Strangely enough, fans of both shows get along pretty well though.
Probably because the reason they got into watching one show was because the others were on the same channel.
Pac-Man Fever: Chris is shown playing a video game by holding an Xbox controller upside-down◊. The quickness with which Dan beats the ... level? Stage? ... when he takes over (also holding the controller upside-down) might also count, depending on what kind of game it's supposed to be.
Palette Swap: Often done as a cheap way to make background characters. For instance, the guy who gets hit by the bus in "New Mexico" is clearly seen with new hair and shirt colors in "Baseball" as one of the members of the seating feud.
Paper-Thin Disguise: Used by Dan and Chris on several occasions, but probably most hilariously in "Elise's Parents", when a very-obviously male undercover cop poses as Dan's girlfriend and Elise's parents don't seem to notice.
Police Are Useless: In "Burgerphile", when Jeff tries to have Dan arrested, the cops try asking Dan nicely to unchain himself from the cash register, and when he refuses, they immediately give up and leave.
Justified, as this takes place in America, and Dan was exercising his 1st Amendment right of a non-violent protest. He wasn't doing anything illegal, so they couldn't arrest him.
Neatly subverted in "The Wolfman"—Dan and Chris are chasing after a child, and pass right by a Donut Eating Cop. He ignores it but then does a Double Take, proclaiming "Oh, right, I'm a cop." Smash Cut to Chris and Dan in a jail cell.
"I didn't ask you to build an animal jail across the street. Shut your prisoners up, warden!"
Protagonist-Centered Morality: Played with and Inverted. While the scripts are occasionally favorable to him, it's made very clear that Dan is nearly always in the wrong... and is sometimes blamed for doing things that aren't his fault. Dan is berated by Elise for sending an innocent man to prison for his crimes... when that "innocent man" stole Dan's identity. In "Family Cruise," Elise's Mom notes how it's Dan's fault the ship is sinking... when she and Elise broke the navigation system.
Purple Eyes: Elise and the androids, brainwashed Elise has a different shade of purple in "Technology" have these.
Dan taking out his revenge list and adding something new to it in the middle of revenge missions.
Dan knocking a glass off the table and breaking it at Chris and Elise's house whenever Chris contradicts him.
Dan unsuccesfully working on inventing a jet pack.
Chris eating things laced with poisons, toxins, intoxicants, etc.
Dan leaving messages for Chris which always contain a rebuttal to something Dan succesfully predicted Elise would say.
The subject of the episode somehow damaging or messing with Dan's car. Especially if it's a location, abstract concept, long-dead historical figure, or something else that shouldn't be physically capable of it.
Serious Business: Chris takes cocoa preparation very seriously, and he does not appreciate being woken up at three in the morning to make it only to have it wasted. He actually manages to intimidate Dan into sitting down and drinking it.
To be fair, if you were woken up in the middle of the night and asked to do something, and the person tried to leave before you could finish doing it (like make them a sandwich), Wouldn't you be a little angry too?
Shaggy Dog Story: "The Wolfman", as Dan and Chris go thorough a month of preparation just so Dan could key his car back.
Shark Pool: One in "Baseball". With squeaky rubber sharks! Dan is not amused. Then there's one with a real shark in "The Beach", which Dan and Chris attempt to "borrow" from the aquarium.
In "The Beach," while looking for the free toy in his cereal, he asks "What's in the box! What's in the bo-ox!". Also the theme and the attacking of Dan's boat when they release the aquarium shark into the ocean is pretty much a homage to Jaws.
A similar version of Quincy Jones' "Ironside" plays during Elise's fight with the android in "Technology".
Also in "Technology," puppet versions of Dan and Chris are named "Dean" and "Moose" respectively.
In the restaurant episode, a family named Dufresne is kidnapped, which is a reference to a Mitch Hedberg routine.
Possibly unintentional but one of Dan's main weapons in the robot battle was his units own torn-off arm, similar to the Gundam Ez8 in the 08th ms team.
In "The Ski Trip", Chris explains to Dan that going forward on skis involves making them like french fries and stopping involves making them like pizza, similar to the ski instructor's speech in "Asspen", an episode of South Park.
In "Burgerphile", Jeff is so focused on having a perfect customer satisfaction record that he'll completely piss off a customer in order to claim that his record is still spotless. Jeremiah Burger calls him out on this at the end of the episode.
The vegans and vegetarians in "Vegetables". It's not stated whether they're on that diet for health or moral reasons, but either way they completely missed the point. The ones in it for health reasons never considered that starving themselves was far worse for their health than eating a steak. And the ones in it for moral reasons had no qualms about eating a broccoli monster, even though it was an intelligent, speaking creature.
Skyward Scream: Dan does one just before each episode title is shown. Occasionally his enemies will do the same after Dan's retribution.
Almost does it a second time in Gigundomart, but realizes halfway through that he already did that.
Smarter Than You Look: Dan is well versed in Shakespeare's works, even naming his teddy bear Brutus. In Dan vs. George Washington it is pointed out that Dan's knowledge can be very intricate, but random. For example when asked who carved Mount Rushmore, he gave the correct name immediately without even thinking about it, as well as the fact that his son had to complete it. However, when asked which U.S. state Mount Rushmore was in, Dan threw out a random guess, Ecuador.
Sticky Situation: Dan gets covered in maple syrup in "Canada", and with lemonade in "The Lemonade Stand Gang".
Elise: Oh, that Dan. Always covered in something.
Strange Minds Think Alike: In "Elise's Parents," when Dan presents a very poorly edited recording of a conversation with Don as evidence that he's a mob boss, he tries to pass off the phrase "cupcake him" as slang for murder. Later, an actual mob boss uses the same phrase.
Stupid Sexy Flanders: Elise's ex, Colby, from "The Family Camping Trip", elicits this reaction in Dan, if Dan's comments are anything to go by.
Subverted Rhyme Every Occasion: Dan gives one at the end of "Ye Olde Shakespeare Dinner Theatre" with an impromptu victory poem, having spoken most of his dialogue in this episode in iambic pentameter.
It lies in ruin, plain for all to see! ... That should teach you not to mess with - DAN!
The Monster Under the Bed has Chris tell Dan that he should be lucky he's not being visited by Uggragoth of the deviantART.
And if that does not convince you of this trope, then Dan's disturbed reaction to the images surely will.
In The Magician, the antagonist was modeled after Chris Angel.
In Stupidity, one of the leading causes of Dan's crusade against the subject matter is a parody of Transformers, complete with the tagline "give up on story, more explosions."
another,smaller, instances of "Take That" in stupidity: "Tv shows just quote older tv shows" a very possible take that to Family Guy.
In Reality TV, Dan dates a woman who he mentions is "the only female wrestling fan he knows that's graduated high school."
A few are directed towards places in southern California.
Chris: City of Industry? What's in City of Industry? Dan: Nothing. Absolutely nothing.
The Tape Knew You Would Say That: In "The Fancy Restaurant", Dan writes a message on the cheesecake Chris and Elise ordered for dessert, telling Chris to meet him in the men's room. Elise comments, "This is weird," and the waiter immediately appears with another cheesecake reading, "It's not weird. Don't listen to Elise."
There Was a Door: After infiltrating the Salvation Armed Forces store to get the file on his accidentally-donated car, Dan breaks the window to get back out, only to remember he'd left the file inside and casually go back in and out through the unlocked door. Revealing not only the broken window but the infiltration plan itself (he had hidden in a chair Chris donated) as pointless.
Too Dumb to Live: In "Stupidity", the antagonist's goal is to lower educational and entertainment standards so that all Americans are too dumb to live. Chris and Dan's near terminal stupidity at the end of the episode (Chris managed to set himself on fire and Dan tried to remove fire ants by beating himself with a two-by-four) convinces him that his job is done and he moves the operation to China.
Even though Chris saved everyone from a serial killer and proved himself a man, Elise's father STILL hates him and swears to get back at him. He's probably angry that Chris one-upped Colby, who's more of a son too, but Colby was ready to let everyone but Elise die.
Unstoppable Rage: Impressively, Dan, in a state of berserker rage, hits a pane of bulletproof glass with his head hard enough to crack it in "Vs. The Bank".
Unwilling Suspension: Dan does this to a costumed kid in "The Wolf-Man" and to the commissioner of baseball in "Baseball".
Weirdness Magnet: Dan. In at least three episodes random beings (including a dinosaur of all things) mess with his car for no reason whatsoever, prompting him to hunt them down, and in another episode he has to deal with a giant tentacled Monster hiding under his bed (this one was actually averted since it was only Chris pulling a prank).
We Want Our Jerk Back: Subverted in "Dan". When Dan seems to have given up on busting the fake Dan and takes the pleasant personality of Biff, Chris is excited and wants it to stay that way. Elise is skeptical, and it seems as if she's going to play the trope straight, but all she really does is remark that "she knew he hadn't changed" when the cops take the Fake Dan away.
Then played straight in "Anger Management". Chris is horrified that Dan (having taken the lessons in Anger Management to heart and found inner peace) won't get payback against Amber for extorting him. When Dan invites him over for herbal tea, Chris says that he doesn't even know who Dan is anymore. Of course, when Dan does go back to normal at the end of the episode, Chris seems more resigned than happy.
What Happened to the Mouse?: Specifically, at the end of "Dance", what happened to Mr. Mumbles? Mr. Mumbles was left alone at Dan's place long enough that, by Chris' account, she was emaciated and not moving. Before a week-long Time Skip. Chris asks what happened to her at the end of the episode, but Dan only turns on TV to show the dance hall getting blown. And she's not seen until two episodes later.
Made explicitly clear what happened to Mr. Mumbles by Chris' remark of "I thought we got rid of all the explosives," and Dan turning on the TV right after Chris asked what happened to Mr. Mumbles. In case you didn't figure it out, Mr. Mumbles went and put them back, continuing the trend of Dan's personality rubbing off on her. And considering Mr. Mumbles is seen again alive and well...
"Elise's Parents" ends up establishing that Elise Sr. is actually a Crime Lord. Even though there are other times it would have been relevant, this doesn't come up again until the next-to-last episode of the third season, "Family Cruise."
What Is This Feeling?: Whenever someone shows Dan kindness, he is often left dumbfounded and not sure how to react.
What the Hell, Hero?: In "Dance", Chris expresses shock that Elise stuffed Dan in a box and mailed him to a ghost town populated by fight-dancing madmen to keep Dan from endangering her chances of winning a dance contest. Doesn't really go anywhere since Elise pacifies him with a shoulder rub.
What Would X Do?: Dan asks himself "What would Mr. Mumbles do?" when trapped on a roof. He then displays cat-like agility by scaling a drainage pipe, landing on the stairway railing, then jumping the remaining distance to the sidewalk. He is amazed it actually worked.