The One Where No One's Ready
(Season 3: episode 2)
Ross frantically tries to get everyone ready for his museum function - but Joey and Chandler fight over chairs and clothes. Monica hears an old message from Richard and thinks it might be new so she leaves him a message, but ends up making things progressively worse. Phoebe's dress gets dirty and Rachel can't decide what to wear so Ross loses his temper with her.
The one where Ross and Rachel kiss for the first time was really good, not the laundromat kiss but the real one at Central Perk...
But my favorite would be TOW The Rumor, it was just plain funny from start to finish, and to hear the back and forth with Ross and Rachel about her "teeny-weeny" and his "affair" with the librarian was HILARIOUS!! :)