Actually, I think the funniest thing on the Internet is Human Tetris:
You know…when I was watching it I thought it looked considerably like a few of the news broadcasts our student news station was responsible for.
That’s pretty dam cool.
I once wanted to send a very good, adult, female friend and muppet fan a pair of beaker panties as a goof and gift but she refused delivery. What say you ladies? Inappropriate or freakin’ hilarious?
If you were to send me some Home of the Whopper Underwear, I would gladly wear them.
John Daker? Really?! Am I the only one who thought this would be a Michael Moorcock reference?
Actually, that guy exemplifies Moorcock’s Daker almost perfectly.
Erekose! Erekose!
Hilarious internet videos are how I get through the night. 
This is just absurd and I have no idea why it makes me laugh: farting pig
I picture my wedding going something like this
Phonetic hilarity (NSFW)
Awesome parody of the iPhone “pilot” ad
Comparable to the horror recut of Office Space…
Passion of the Wii (warning: potentially offensive to some)
Truthfully you probably won’t think this is funny unless you’ve watched both Azumanga Dioh and LOTR:
Go to Animemusicvideos (dot) (com) and do a search for “Lord Of The Yen”.
Alex Navarro playing the worst PC game ever made.
Why y’all gotta be so negative? Can’t we watch a good clean family movie every now and then?
Daniel
Anything that Tay Zonday does, especially this:http://www.youtube.com/watch?v=2x2W12A8Qow
http://www.youtube.com/watch?v=hISY0aKoxwo I like this because I am patriotic.
Don’t watch this at work. For the love of God…
And yes, Channel 102 is worth it, for The Defenders of Stan if nothing else.
I’m hopelessly in love with the Internet, so I’ve got a lot of favourites. One recent one is Jon Lajoie’s videos, particularly Everyday Normal Guy and High as F*ck.
I also recently love these ones:
Total Momsense. - Neatorama (now that I’m a mom)
Did you know that men have landed on the moon?
I just youtubed Carol Burnett, and the first link was to something I’ve heard about but hadn’t seen: Tim Conway’s elephant story. Hee hee hee!
Daniel
This was made in the eighties, long before internet video. Clown Hunt!
The best laughs I’ve had on youtube have resulted from putting the following (on seperate occasions, not all at once!) in the search…
Gervais Podcast
Extras Outtakes
Outtakes
Very Funny Animated Gifs
Bloopers
PowerThirst, responsible for many quoted lines shouted out by airmen in my squadron during PT. 
This classic -
The original location for the End of the World video. ebaumsworld has a bit of a reputation on the internet for blatant disregard for the copyrights of online videos and flash animations, often going so far as to crop the original copyright watermark off of the videos before reposting, and giving the original creators no credit whatsoever.
All of which, of course, brings us to another favorite of mine, complements of ebaumsworldsucks.com: ebaumsworld.com