- YouTube is striaght forward. Content is easy to find. Basic rating system seems to work.
- MySpace is annoying. Can't find anything or anybody on Myspace without joining. Reminds me of the old web days where everyone was trying to use every "feature" in html for the sake of using it. Big (i.e. Large) wallpapers. Annoying music and every possible flashing/blinking light known to the web.
I think YouTube is doing the google thing by keeping it simple.
Here is an article which discusses that YouTube has now taken over the lead in community building websites. Pretty good read: