Josh's reactions to whenever a guy begins to hit on him. Heck, his reaction to when girls start hitting on him are hilarious. He always gets so flustered, though he tries to stay calm.
Rodney's stories of... past boyfriend tend to be rather amusing. Especially the one where he decided it was over once his boyfriend started asking to be breast fed.
The scene where Burt discover's Kevin has a Hello Kitty thong. There is much teasing from Burt's end, and it ends with Burt leaving the thong on a frazzled Kevin's muzzle and taking photographic evidence of it.
The fact that Trent pretended he was taking his brother into an adult club, when in fact it was for all ages. He had done it all out of a desire to make him look like he could do anything for his brother.
Also the fact that Josh never realized that it wasn't an adult club he had gone into.