After playing through Tony Hawk, I skipped 2 and jumped right into 3 on the XBox. I can say that I am pleased. The game is essentially the same at the core, but it offers so much more depth and quality that it's hard to ignore. The first night I played it for a good couple of hours and then fell asleep in front of the television with the game still on. So yeah...it's addictive.
If you've never played Tony Hawk, then you should grab this one and see what all the hubbub is about. If you're already a Tony Hawk fan, you may be less inclined to purchase this version, but it's still a great buy. Especially since XBox owners can make their own soundtracks (man I love that).