Best Gpu for around $100-$130

APPROXIMATE PURCHASE DATE: Sometime this summer maybe more soon, maybe later Budget: Total $550 MAX. (am at around $410 with hard drive and media disk)
I will be using this mainly for everyday computing and moderate games like minecraft, WoW and might buy a higher graphic demanding game like skyrim or bf3.

CURRENT GPU AND POWER SUPPLY:Going to buy A 500w Psu and dont currently have a gpu. (building a new computer)

OTHER RELEVANT SYSTEM SPECS:
I'm going to have these parts:
Cpu: AMD Phenom II X4 955 Black Edition (125W) Quad Core Socket AM3
MoBo: Asus M4A78LT-M LE Socket AM3 AMD 760G Chipset
Psu: Topower TOP-500PM Nano Series 500W PSU
RAM: G.SKILL Sniper Series DDR3 1600MHz (PC3-12800) 8GB (2x4GB) Dual Channel Kit (F3-12800CL9D-8GBSR)

PREFERRED WEBSITE(S) FOR PARTS: http://www.canadacomputers.com (basically anywhere i can get a good deal for all my choices, so I guess newegg will work too.)

PARTS PREFERENCES: Does not matter, have more knowledge on the AMD HD series though.

OVERCLOCKING: O/C: If its worth it, Sli/Crossfire: probably not

MONITOR RESOLUTION: 1680x1050 21.5"


ADDITIONAL COMMENTS: I have little knowledge so please explain to me in detail of why you choose that gpu.

If you want the links then I can post them in.