Hoping there's enough time to get some replies to this thread.

On one of the last OT days a similar thread kept me amused for a while. And I believe it was COTH where I first came across Llamas With Hats.

Cats With Thumbs: http://www.youtube.com/watch?v=h6CcxJQq1x8

Gay Men Will Marry Your Girlfriends: http://www.youtube.com/watch?v=X-YCdcnf_P8

Cat Friend vs Dog Friend: http://www.youtube.com/watch?feature...&v=GbycvPwr1Wg

Call of Duty Black Ops ad (the Replacer): http://www.youtube.com/watch?v=5lmy0Kk8tM4

Battlefield Friends (if you don't play games like Black Ops, Battlefield, etc online this probably won't be as funny to you):
http://www.youtube.com/watch?v=aU-4YyLuUdI