Heavyweights/Awesome

The dance. Starts out as awkward as you'd expect given fat, geeky campers with image problems and good-looking girls, but between the disco music and the bad dancing, everyone starts having fun. Doubles as a Funny Moment as well.
The food-for-all after Tony has been imprisoned. Admit it, as a kid, dancing around a giant bonfire while chowing own on everything is a dream come true.
Pat giving his impassioned speech about the campers taking responsibility for themselves, followed by the montage of everyone doing just that.
Jerry's Dad knocking Tony out:

Jerry's Dad: You're wrong! You are THROUGH HERE!

Pat leaving Tony in the jail the kids set up. Pat had just found out the kids had imprisoned Tony and noticing the incredible illegalities of this, tries to let him out... when Tony makes the mistake of insulting Pat and threating to castrate him. Pat promptly regags Tony and asks if the kids are sure the ropes are tight enough.
The British Kid during the apache relay. While the other camp was able to get ahead based on physical ability, when they get to the Tent of Knowledge, their promplty stumped by the questions... which the British kid passes in no time flat and puts Camp Hope ahead.
- Even more hilariously, he's a British kid answering questions about American history. How many Vice Presidents can you name? (This was before Al Gore, Dick Cheney, and Joe Biden really started standing out.)