Processor:- Pentium Dual Core E5200 2.5 Ghz
RAM:- 2 GB DDR2 667 MHz
HDD:- 80 GB 7200 RPM
OS:- Windows 7 Build 7000 BETA
Monitor:- AOC 18.5 INCH ,resolution 1366 x 768
Please suggest me a graphic card, keeping in mind the resolution of monitor. I want the cheapest!