The newest one is Tony Hawk Shred. However, it is nothing like the older Tony Hawk games, as it uses a skating peripheral and is aimed toward a younger audience. Same with the one before it, Tony Hawk Ride. If you want to play a game like the older one's, there's Tony Hawk Proving Ground and Tony Hawk's Project 8. I recommended those two over the newest ones (if you haven't played them yet)...
i have not been playing any hawk games lately what is the newest one.
THhred. It uses the same skateboard peripheral as TH:Ride. So, if you have Ride's board, there's no need to buy the board again. I'd use caution before buying Shred though, it's aimed towards kids and like I said it uses the skateboard peripheral as the only way to control the game.
If your a fan of the classic controller and aren't used to the board, you will probably not like either TH:Ride or Shred.