I know it's a total gimmick but the Ron Burgundy interviews really crack me up. He brings his unique interview style to people like Rebeccca Romijn Stamos, Michigan State coach H to the Izzo (kinda random tho), and Jesus Christ.
Also, for Will Ferrell fans, check out this clip of a never publicly aired character that he created rocking out with Diddy during one of his SNL rehearsals as he's "rapping" the worst song I've ever heard. It's really a terrible thing.
And on Funny or Die (the website that the aforementioned clips above are taken from), Will Ferrell's venture into new media, this clip introducing Judd Apatow's (the guy behind Knocked Up and Superbad) enlistment is high-lar-ious.
Along with leveraging the PR buzz and industry connection of its founder Will Ferrell, as well as providing an alternative creative outlet for comedians, writers, and actors (with more top-down legal protection I bet than YouTube), Funny or Die is trying to position itself or rather muscle its way into being the YouTube of professional comedy. Despite its awful name, it has a few positives or advantageous that brings me back repeatedly to the website. For one, the actual playback video quality is clearer than YouTube, but loads just as quickly. And secondly, I find a lot of the content pretty hilarious. That said, the site would probably be very popular if it was nothing but Will Ferrell.