I must admit that I am not an iTunes junkie lost most but I can say that I really enjoyed the iLike service in terms of discovering music that was actually in line with my tastes. They recommended numerous types of music based on multiple variables and they actually got it right! Can you believe it? Feature wise, they have the most robust recommendation engine of all of the music discovery sites and base recommendations is a "Sounds Like" methodology that they use in conjunction with your listening activity through iTunes. They combine this information and make pretty good music recommendations. They also recommend music based on what your friends like which is also cool.