There is currently no Nvidia DX11 card that is under or close to your budget, at least not on the Egg. Their closest matches are the GTX465 cards on offer at about $250.
The best DX11 card within budget is the HD5770, the next is the slower HD5750.
Why the slavering, rabid, twitching, manic and insane hatred of the poor defenceless, innocent and wonderful HD5770 anyway?
@ct1615: Yes, how the mighty do fall!
i will be gaming at 1280x1024 i love crysis warhead i want to play on miximum setting on 1280x1024
some people said that i cant game at maximum settings with 5770 so there should be something under 200$,230$ or 250$ with could max everything out
dx 11 remember
my specs r q8400
4 gb ram
550 watt psu
gfx 8800gt currently
i assume you mean maximum settings and not minimum since the 8800GT can play crysis on medium settings at 1280x1024. The 5750 can easily play crysis at high settings at 1280x1024, the 5770 at very high.
The HD5770 is fantastic for your resolution and will be able to handle Crysis Warhead on max settings but you will have to leave AA off. If you want something that can max out AA then you will want to up your budget to $300 and get an HD5850 but that card is ludicrously overpowered for a 1280x1024 monitor.
For the current monitor, the absolute best choice is a $150 ATI 5770.
An ATI 5830, 5850, GTX 465, would all be wasted on the monitor (not to mention over $200 budget).
I guess, even after reading the posts, I don't understand why the OP is adamant about ruling out the ATI 5770 (which is really the best option).
Also, keep in mind, sticking with DX11 only options and having a $200 budget doesn't work very well. Yes the ATI 5770 is a superb graphics card for your resolution, but once you play DX11 titles, the 5770 is at the low end of DX11 cards in the first generation of DX11 cards.
I'd still say get the 5770, but not because it's DX11. Get it because it's the best performance/value for what you're saying you want.