Eye of Argon MST (NSFW)
The story by itself is amusingly bad. With added commentary by Adam Cadre, it's hilarious.

Issendai's Lair
Humor lists and general silliness abound. This is a fun place to spend an afternoon.

The Legendary Lily Pad
Best. Flash movies. Ever. If you haven't yet been there, go now. Now, I say!