The only parts I need left for my pc are the GPU and PSU. I'd like to run games like Watch Dogs and Crysis 3 at max/near-max settings at 1600p (or 1440p). I have an i5 4670k and I'm going to OC it to 4.4GHz.
What kind of GPU can hold me off with awesome performance for 3-4 years, and what kind of PSU would you guys recommend with it?
Honestly I don't think there are ANY gpu's that will old you off at 1600p ultra for 3-4 years. Even if you got the current best GPU (GTX 780 Ti) it would probably only hold out for 2 years or so. The 780 Ti can only play demanding games on 1600p ultra at 40-50 fps average CURRENTLY, in 3-4 years you will have to be playing on medium settings most likely.
Okay, if I were to go for 1080p max instead, what would be a good choice? I've seen stuff like the ROG MARS 760 and POSEIDON 780 but that might be overkill? I don't know.
And my budget can go as high as $650
I would go for one of the 780's with that budget. Or if you don't mind running an AMD card, a 290X would be a good fit for the budget.
OR if you don't mind stepping up a little bit, the GTX 780 Ti would be the most futureproof option, but the price is around $700. The EVGA 780 Ti SC w/ ACX just recently dropped to $709 on amazon, that's the one I picked up. I'm very satisfied with it. Crushes just about everything at 1080p. he most demanding game I own, BF4, gets a solid 65+ fps, average around 85. Amazon offers 12 month no-interest financing for large purchases...