Laurel and Hardy crack me up, especially in March of The Wooden Soldiers. I love movies like The Women(which is heavy at times, but funny in that "you-go-girl" fashion) and The Philadelphia Story. The Gidget movies are also pretty funny, but more in the that's- so-cheesy-it's funny way.
I'm taking a class on Shakespeare's comedies this semester, and I must say that the man knows good comedy.