Need a Good Gaming Desktop/PC Build for around $550

My poor old 3-4 year $400 laptop just broke on me yesterday so I am looking for a new wife. My budget range is around $550 and I am looking for a desktop (or even a laptop) so that I won't have to play every game on the lowest settings. I will be playing LoL, Team Fortress 2, and Skyrim on it so nothing really heavy duty. I am not that savvy with computer specs and building computers, but I sure know a lot of you are.. If you have any great builds or computer suggestions out there please please please post them below!

-Leafy