I am on Lala right now listening to Walls of Jericho by Helloween. Lala was awesome because you could find some really old off the wall stuff, listen to the entire CD, and purchase. The worst thing is buying a CD because that 30 second clip sounded bad ass to find out the rest of the song was garbage. What lala did was offered people the ability to try-before-you-buy without resulting to torrents. If Apple integrates with itunes I hope it stays web based. Lala was a great service but I knew this day would come once Apple bought them out.
I loved the Lala feature to listen to a song in it's entirety but they also took it further with amazing integration for connecting with friends, seeing what they were listening to, and recommending songs to them.
On top of that, Lala allowed you to purchase the streaming rights for 10 cents which really got me buying a lot more music that I would never want to own, but would listen to then because it was pertinent to my mood.