Well, post 'em if you got 'em!
1. Post a description along with your link. Something more than "lol" please
2. Be sure to go through the thread or use search to make sure you're not posting duplicates
3. Don't post more than three or so at a time to keep from flooding the thread
4. Rickroll and the like will get you a two day ban! DON'T DO IT.
5. Watch YouTubes and have fun
Okay, I'll start...
This is the funniest thing I've seen in a while. Voices dubbed over Star Trek: TNG, and it's done really well:
A hilarious review of Phantom Menace in seven parts (yes, it's 70 minutes long, but totally worth watching every minute):