The fic as a whole, really. At over 100 chapters, there's much too much hilarity to list it all.
Try to get through the first three chapters ALONE without bursting into hysterical laughter. And let's see you keep a straight face when you read this:
"Conner, you're not helping," Ethan said dryly. He looked at Conner, Kira and Trent in turn, and then all four of them turned to look at Tommy. Something about the gleam in Ethan, Conner and Kira's eyes made Tommy take a nervous step backward. "Guys," Ethan grinned in an almost maniacal way, "I think it's time we tried a little something called teamwork."
Tommy's eyes darted to the door, not knowing what they were planning but knowing he didn't want to be around for it. Just as he decided he could make it to the door if he dodged between Kira and Trent, Conner shouted, "Everyone grab a limb!" and Conner, Kira and Ethan leaped at him.
Ethan seized Tommy's right arm, hugging it to him tightly, while Conner and Kira each grabbed a leg and held on like two year olds trying to prevent Daddy going to work and leaving them at day care.
Then there's this line in this next scene
Ethan was now holding his right arm and the end of his left sleeve, preventing him from using either arm (not surprising, considering how often Tommy had spontaneously started hitting him.
Not to mention the main three rangers playing keep away with Tommy's phone, while talking to Jason.
The power rangers day parade is a collection of multiple Crowning moments of funny; first is Billy and Goldar taking turns chasing and running away from each other, Trini trying to kill Zack because he won't stop laughing, the zords crashing into each other resulting in the Rangers having to tow them, Jason becoming the spokesperson for Kinko's and then Tommy being used as a distraction so they can get away, bonus points for the rangers forgetting him for a while.
There's also the follow-up, featuring Billy being mistaken for the Red Ranger, Jason firing his Blade Blaster into the roof of Angel Grove High and Kim using the Power Bow to break up a Tommy/Jason deathmatch.
The explanation of why Tommy cut his hair involves Tommy being set on fire, getting covered in tomato sauce and gunk from a fire extinguisher and going to visit Hayley in the middle of her English class.
"Hair," Tommy croaked. "Fire. Job. Tomato. Water. Anthony. Bwoosh. Hair."
The flashback to the aftermath of Forever Red. Trini getting very angry at Jason and Tommy for going off without her and terrifying the hell out of all the Red Rangers. You will NEVER be able to watch Forever Red the same way again knowing that just as the camera fades out, Trini is charging in...
She makes Eric, the Quantum Ranger, scream in fear. Let me rephrase that: The Quantum Ranger is a sixth ranger, who is almost always more powerful than the normal rangers. Throughout Time Force, he's been shown as a powerful, unflinching badass. In the season finale of Time Force, he took a shot to the chest- unmorphed- in order to protect Wes's father. And TRINI is the one to make him scream. Beware the Nice Ones indeed.
Rangers vs. Clowns. Especially because it's started by Trini, The Heart of the team. It's especially funny because it's rooted in canon (an evil monster-disguised-as-clown turned her cousin into a cardboard cut-out). It ties in with an earlier brilliant moment when they had to cover for their antics by pretending to be clowns.
Adam wields a stuffed frog (a great continuity gag) against a clown armed with flaming sticks.
Chapter 118 mostly focuses on the rematch and starts off with Cam and Justin incredulously watching Adam and Rocky chased by clowns and other carnies. Their conversation about what they just saw is hilarious enough, but then comes the actual rematch, pitting the carnies against Adam, Conner, Justin, Kat and Rocky. The scene gets really creative in seeing how the Rangers battle not just the clowns but their allies, too.
After a long string of incidents at the Angel Grove Mall—including the first floor flooding thanks to a fountain of the Rangers being destroyed—Conner has gone missing. As we soon find out, he ends up helping Bulk and Skull with their stolen chimp. The Dino Thunder Rangers ask Ethan to use his Retroactive Wish skills to get Conner to reappear. Moments later, a Red Dino Thunder Ranger action figure falls into the fountain. They all look up... and it turns out that a toddler had dropped it down.
During a ranger party at Adam and Tanya's house space pirates attack, after everybody's had a few too many drinks. It takes them a bit longer than usual to morph becuase they have to figure out who goes in what order.
Billy (of all people!) is so hammered that he doesn't even morph until Zeo is nearly finished... a good seven or eight spaces too late.
This infamous line by Jason: "I love my wife. And she needs her chainsaw." The italics are intentional.
After drinking Aquitian water and beer and not getting enough sleep, Rocky and Adam suffer some... bizarre side-effects. Every five minutes, Rocky pops up and sings a deranged variant of "I'm A Little Teapot" (when it wears off, he feels the need to go to a tea shop...) Adam, meanwhile, dreams about dancing wildebeests, forcing Kim to sing him to sleep with a lullaby.
Let's not forget Conner's attempt at ordering porn in the hotel.
Trent loses it over a bunch of hamsters in the mall pet shop.
Chapter 57 has a subtle moment- Anna (a friend of Tommy's) older sister, Emily, married this guy named Rick, who was skittish about dating after a jealous guy beat him up over a girl. It turns funny when you realize that Emily is Jason's ex and Rick is Richie, who Jason beat up over Trini.