Just to sprinkle a little estrogen on this list:

Intolerable Cruelty
Legally Blonde (I often channel Elle Woods)
Saving Grace (brit flick)
Princess Bride
and Some Like it Hot

Mr Deeds is a current slapstick fave - possibly because the soundtrack is so good. I think that was most of the appeal of the Wedding Singer too, another perfect hung-over-Sunday-afternoon movie . . .