The phrase "worst MySpace page" would seem to be redundant; nevertheless, zefrank launched a contest to find it.
Most of the entries seem to have been put up expressly for the contest. They've now reverted to standard MySpace format (which is no thing of beauty itself) or allude to the joke by including zefrank's tricolor duck motif in the design.
Still, there seem to be a few that are for real, like this eye-poppingly (Warning: May induce epileptic fit, even if you're not epileptic.) bad design. That is, I think it's real, but it's impossible to read, so who knows?
If you haven't experienced the exquisite banality of MySpace yet, zefrank's "winners" page would be the place to start. Warning: Many of the links have embedded music.