It depends. If you laptop is made for Vista stick with Vista. I recommend in your situation the next: Stick with 7 and dual boot XP for your games. You will love it!
I have Windows Vista and I must admit id rather get Windows 7 (can't afford it right now), so my best suggestion to you would be to stick with 7.
I have Vista and have no problems with it. It all depends on what software you are going to install afterwards. But to be real XP has least problems of them all.