Courtesy of Deirdre Straughan, here's a site that tests a lot of video players in one spot. Some of them load automatically, so you'll have to scroll down and pause. You'll be greeted by some cool music. Thanks, Deirdre, for bringing this to our attention and doing the testing that the rest of us are too lazy to do!
For more comments on various video sites, check out Loaded Pun. Great resource on the pro's and con's of each site.