What games do you have in mind to play? If you're talking stuff like FEAR and demanding games, then what everyone's saying is pretty much the truth, but if you're wanting to play games of a bit more kind in nature on a system like... idk, CSS, Swat, older games, games that don't require 1 gig of ram and a 256M graphics card, almost any laptop will do you fine.
That's pretty much what I got my laptop for, to be able to play games, but I needed something reliable for college. So I chose the 1505 for it's features, and it's smaller than the 1705 so it's lighter and not as bulky. From there, just upgrade things to get the type of performance you want... if you want a basic system that will play your average game on medium settings, get a Core2Duo, 1GB Ram, and upgrade to a dedicated graphics card.
But if you're wanting to have a really nice system that will do what you want just not for every game, get the best processor, I think that's the T7200, but they may have one better now, 2G of ram, 120GB HDD, WSXGA screen, the best graphics card, etc. You'll be able to do all of your standard tasks super fast, and you'll be able to play most games... just don't expect to do it on the highest settings.