780s for about the same price as a 290(http://www.newegg.com/Product/ProductList.aspx?Submit=ENE&DEPA=0&Order=BESTMATCH&Description=radeon+290&N=-1&isNodeId=1) but with better cooler because the 290s dont have non-reference coolers yet. I know the 290 has a larger memory bus and more vram(which at 1080p even 144hz probably dosent make much difference its more 1440p iirc where that matters) , but looking at the benches it seemed the 780 did pull a tiny bit ahead of the 290. Last month it was clear which of them was the better bang per buck but now I don't really know. I was getting ready to get a 290 but now I don't know man.
The GTX 780 dropped in price about a week or two after the 290X was introduced in response to the pricing. In the stock price/performance arena, the 290 dominates; it gets very close to 780 performance and beats it in most 4K cases. However, the noise and heat is a really big issue for me as it runs up to 95 C and there hasn't been any 3rd party cards released yet with their built-in cooling solutions. Power is another: the 290/x is one thirsty mofo.
That being said, there are water block and aftermarket cooling solutions available that definitely improve the noise and heat issue. If you don't mind voiding your warranty, paying $50 for one of those, and the work involved, then the 290 with the aftermarket cooling solutions is not a bad deal.
Just be aware that the 290/x is definitely not good at overclocking. The 780 is an OK overclocker from what I've read.
Personally, the GTX 780 is a better choice as it is quieter and less thirsty than the 290 and it can overclock better. It's up to you one with which one you want.