last.fm - they got it right.

I'm never one to rave about a particular website, but last.fm are worthy of huge credit. The last.fm site not only looks superb, but the range of music and the wealth of information on different artists is amazing. They have absolutely nailed the key elements of community-driven sites, with twiki-style artist bio's, tagging, shoutbox/comments, playlists and profiles - all presented in an un-imposing, meaningful way.

There are still some wrinkles in the navigation, but the site improves week by week. I'm impressed.