Most powerful video card for under $200?

My current specs:

• Pentium Dual Core E5200 3.25GHz
• Radeon HD 4670 512MB
• 4 GB RAM

I plan to do an all-around CPU, GPU, and RAM upgrade within a year. However my current GPU is a holdover from before I built my current machine (plus it was a pretty weak budget card back in 2008 ), and the bottleneck it creates is driving me INSANE. I know it's a bad idea to buy one part before all the rest, but I just really want a serious GPU right now and I don't know when I can do the all-around upgrade. Might be in a couple months, might be this time next year. Meanwhile I'm dealing with erratic framerate in games like DXHR, Borderlands, and The Witcher, and Bad Company 2 is unplayable.

So what card can I get for $200 or under right now that will last me at least a couple years?

hd 6870

The Nvidia GTX470 I would personally say is the best buy boss.

HD 6870 or GTX 560 (non-Ti)

6870 looks good. Probably going to spring for that.

Thanks, all.

EDIT: By the way, this is a very nice deal - $175, free shipping, free copy of Deus Ex HR, and $10 off if you use the code "NEWCUSTOMER10" (it's for 'new customers', but I made a new account and it worked, lol).

Hd 6870 deffinately but the Hd 6850s are no slouches either.