http://litfusefilms.com/movies/
I just recently discovered Lit Fuse Films, and their G-Mod videos are both inspiring and funny. I especially like Ignis Solus, Combine Nation, and the feature-length War of the Servers (a War of the Worlds parody, without a Scientology nutjob as the main actor).

What are you favorite memorable videos? Link to YouTube or whatever, but be sure to add a description, and be sure to follow the Org rules.