I have been a Myspace user for years but 3 months back I have switched to Facebook and experienced Facebook to be more friendly and spam free. I won't get friend request anymore by anonymous user. SO, I can say Facebook works for me.
Facebook is the best. The first and the most imp. thing is less spammers as compared to Myspace. I don't get request from random people. Moreover Facebook provides with lots of application to which I am edited.
I use both. I typically only use myspace for music. For all my other social networking needs, I definitely prefer facebook. There's so much spam on myspace, it's no wonder it has lost its popularity.