I would say Monica. She is so insane, but also my favorite character. She blurts out at Rachel's baby shower "I have to go powder my ass!", when Rachel says "Phoebe's" pregnancy is not as important as her wedding she says "Of course not- nothing is!", she is willing to stick her head in between her maid's legs and then tells her she is very attracted to her, she hides lottery tickets in her bra and keeps them from her friends. I love how crazy she is!

Joey. There are times when even the other characters think he's being out of line. He's so earnest.

I'd have to say Phoebe because she will come out and tell someone when she thinks they have done something stupid, or are wearing something that doesn't match, or just her opinion about a person.

Phoebe definitely

Crass implies disregard for people's feelings, in that case it has to be Monica.

Monica definetly! Even though she is my favorite character! She is open minded and she goes crazy when people are mad at her! She will do anything to see if somebody has stolen her jeans! She thinks everything she does is perfect and nothing is better than her! :D