im not sure about what gpu to get right now but ill be using onboard graphics for now (radeon hd 4250)
i want to be able to play mostly minecraft and league of legends for now but later ill be playing tf2 and maybe a bit of crysis 2 on mid settings. thanks for your help
You can always consider a trinity for low budget gaming at decent low to mid level performance. Unfortunately for gaming the most important componant is the graphics card, you can alternatively look through Amazon and other classifieds and pick up a mighty cheap Phenom II x 4 955 BE and use the savings towards a low cost GPU.
You also don't need 8GB RAM you can get by with 4GB of DDR3 1333, and a antec earthwatts 400w unit is more than enough for a low cost budget build.