It really depends on your budget and personal preference. The two best gaming CPU's in terms of performance for the money are the i5-3570k (4670k) and FX-8350 which roll in around $200-$240, respectively. Neither of these will bottleneck even the most powerful GPU's (Titan, etc.) and both are overclockable.
If on more of a budget, I would suggest nothing lower than an i5-3350 or FX-6350, if you still want very good performance. Anything less than that, stick with AMD and overclock as much as you can. Intel really doesn't have many strong budget CPU's as their lower-end offerings seem to only be dual-core parts. IMHO, dual cores, even with hyper-threading, just won't cut it anymore in terms of gaming, going forward.
Both have their advantages and disadvantages. The i5's are stronger in stock form, but the AMD's catch up no problem with overclocking. Personally, if I were to build a system on a tighter budget, I would build an AMD system mainly for the cost/performance value. Intel makes nothing in the $120-150 range than can compete with the FX-6350. Again, the core i3's *might* keep up in certain games, but that is a quickly diminishing light moving into the future where more cores will become essential for gaming.
The APU's from AMD, while somewhat impressive (compared to IGPU's of the past), they require higher speed RAM (2133 for the A10-6800k) for the best performance, which is more expensive. If you factor in the cost for the A10-6800k and the more expensive RAM required, you'd be better off with an Athlon X4 750k, cheaper 1600 RAM and discrete GPU like an HD 7770/7850 or similar for the same amount. That combo will blow the A10 out of the water. But don't get me wrong, the APU's have their place, but here were talking in terms of more heavy gamers on a budget. APU's IMO are not quite there just yet.
Boiling it all down, AMD is actually in a great position at the moment and there are many reasons to go that route. They have the low-end and mid-range gaming market pinned as all their CPU's are at least quad core parts with a ton of overclocking potential, while Intel only has dual-core offerings on anything new below $180. In terms of mid to high-end gaming, AMD is very competitive with the 8350 (which, btw is compatible with faster 1866 RAM if you want that little extra edge).
Power consumption, I think people make a bigger deal out of this than it really is. The difference isn't so drastic and if you're like me, you care more about the performance than a few extra watts under heavy load.
I'm going with an i5-4670K for my build, but a major part of that decision came from the fact that there are no AM3+ (AMD FX series) motherboards in the m-ITX form factor, and I'm building a Fractal Design Node 304 gaming rig in the $1200 range, thus, I don't have much of a choice. If I had to chose between the 8350 and 4670k, it would be a difficult decision for me (not that I wouldn't be happy with the 4670k...).
Going back to personal preference; what is it you'll be doing with the machine? What form factor? Are you energy-conscious or do you just want the best performance per dollar? Are you in to overclocking or prefer to just build it and leave it? Weigh all the options, compare apple to apples, ask questions and make your decision based on facts, not fluff.
(Before anyone jumps on me, please note the prices I stated are Canadian)