i agree. get a card based on the 6600gt or higher gpu. i reccomend purchasing an msi model (www.msicomputer.com, from both professional and personal experiences.
I've never used MSI but im sure it is a good buy, but as for a Gigabyte graphics card i would say they are pretty good, I am running a Radeon X800XT by Gigabyte and its been runing great since the day i bought it.