Critical Metrics (bonus points for anyone that can tell me what their logo is supposed to mean) is an intriguing new site that aggregates data from a variety of sources to provide the first usefull music recomendations I've found so far.  From their About: "Every week, artists, DJs, music tv networks, newspapers, magazines, retailers, and bloggers recommend hundreds of their favorite new songs.  Critical Metrics keeps track of recommendations and playlists across all media so you can easily find, try, and buy the best new music."

The site is well-built and intuitive to use.  The key thing here is that it actually provides a usefull service!