Oh come now, the Student Council President "translating" Sousuke's lines into street in the first episode. Chris Ayres' deadpan delivery in the dub is priceless.
President Hayashimizu: "Now listen, you punk, there's no way you'd beat me, so step off, 'cause you ain't even got one chance in a billion, you loser bi-otch."
Sousuke: "Your language skills are outstanding, Your Excellency!"
Also the slo-mo fight between Sousuke and a horde of Bond henchman knockoffs.
And the wacky chase scene with the nutso cop lady.
Sousuke: "...Mens' and Womens' baths change at 10."
Don't forget Sousuke's complete inability to play arcade shooter games: He runs out of ammo so pulls out a real gun and blows holes in the screen. But the punchline is, when asked why he didn't just reload by aiming and firing offscreen, he responds:
And his failure in playing a Dating Sim when he chose not to help the girl in the game shop for a swimsuit.
Screen: "GAME OVER."
Sousuke: "Wait! If you cut off negotiations from one side, it will become a war! Accept the negotiations, I'll listen to anything you have to say! We should compromise a little bit. [beat] Where did Chidori and the others go?"
That episode was beautiful. It had Sousuke in a box, rugby team ass-kicking, and Sousuke's awesome and absolutely hilarious motivational training monologue, courtesy of a book from Mao.
Sousuke leading a group of yakuza into a highly fortified enemy stronghold to rescue Kaname, he and his elite team using SWAT-style Close Quarters Battle tactics against the enemy... while wearing amusement park mascot costumes.
Not strictly part of the anime, but this review of FMP contains the most eloquent summary of Sousuke's attitude towards his captain at 6:00. DO NOT WANT [edges away] WANT [edges forward] DO NOT WANT [edges away] WANT [edges forward] DO NOT WANT [edges away] WANT [edges forward]
Any scene involving the Police Lady's involvements with Sousuke. Especially in her fight with Bonta-kun!Sousuke, someone was having a little too much fun.
Tessa explaining her credentials:
Tessa: "I'm a submariner! In other words, getting wet is my business."
Kaname: "Ooh. Poor choice of words."
Tessa tries to kiss Sousuke in Fumoffu when he was dragged unconscious out of the school pool after belly-flopping in to try and save her which is funny enough on its own. She loudly and dramatically declares that he needs CPR and as she leans in to put her mouth to his before Kaname pulls her back by the hair and angrily points out that he doesn't need it.