To run some newer games that eat up a lot of memory, you need to be prepared with at least 2GB of RAM, else, you may hit Swap and the performance will degrade really bad, even more than in Windows. A nVidia video card is highly recommended, as their proprietary video driver works best with wine. You just need to make sure your machine is working fine. It won't work if your specific Video Driver + Kernel has a bug that makes the performance go downhill.
And you may consider purchasing CrossOver Games, although their GUI is really messed up and they only officially support a few games, if you want the minimum amount of effort possible and maximum performance, you should consider it. And they contribute directly to the Wine project.
And if, you dig up and get your hands dirty, you can run some problematic games like Worms Armageddon and Age of Empires 2.