Have a read of my draft ti0, you might find it helps:
The difference between AMD and intel for gaming.
Firstly, you need to decide what your priorities are, and what you will use the PC for.
Things such as: light gaming, heavy gaming, basic work (e.g. MS Office), heavy work (e.g. video editing, 3d modeling). For the most part in current games the biggest difference will be made by the selection of the GPU. Get a great GPU + worse CPU rather than worse GPU + great CPU.
The AMD FX CPU's have many cores, which are weaker.
intel i5's have less cores, which are stronger.
The intel's consequently have better performance per core. In older games, the intels perform much better as those games are optimised for good performance with only a few cores (single-threading).
In newer games, the AMD FX's really shine due to the introduction of games using more cores (multi-threading).
The difference comes in depending on what you want to use the PC for. If you're on a tight budget, save some money and go with the AMD and spend the extra money on a better GPU that will give you better performance than any CPU could.
i5: Good for older games (single-threaded), Good for newer games (multi-threaded), Good for general work, great all-round CPU and probably the best around for current games (may change in future, see here: http://www.corsair.com/blog/ps4-xbone-pcgaming/ ).
AMD: Slightly worse for older games (single-threaded), Great for newer games (multi-threaded e.g. BF4, Crysis 3), Good for light/heavy work, extra cores are great for 3d modeling and video editing or rendering, great CPU whilst costing much less than the intel. Even though it's worse in older games it will run them perfectly well and smoothly.
Regardless, both will perform well.
For an i5, I would recommend an i5 3570k or a 4670k. Why? They are king for gaming performance at the moment and since they are the k version they are unlocked and can be overclocked in future for a performance boost.
For an AMD, I would recommend a FX 6300/8320/8350 [Do NOT go with a bulldozer CPU, only piledriver. List here: http://en.wikipedia.org/wiki/Piledriver_(microarchitecture) <-- That should all be one link, not sure why it splits.]. Why? Great multi-threaded performance for newer games and heavy work, are just fine in older games (not overkill, can deliver smooth frame rates maxed with a good GPU), and are great for productivity with a tame pricetag.
In conclusion, budget gaming/work: AMD. Not on a budget gaming/work: i5. The i5 currently delivers better performance but don't get the impression that the AMD is lagging behind. They are great for gaming and work with a really great pricetag, just not currently up there with intel. In newer games though such as BF4 the AMD's have caught up in performance and in some cases deliver better performance than the intel's for much less money. You will get great, smooth FPS with either.
Either solution will game just fine with a nice GPU, focus mainly on that.
As for nextgen, it is difficult to speculate. Next gen games may/may not be optimised for multicore cpu's such as the FX so they can get more performance. Games like Watch Dogs and BF4 are highly multithreaded but that does not necessarily speak true of all games. However, take a look at this: http://www.corsair.com/blog/ps4-xbone-pcgaming/
The i5 has 4 beefy cores and the FX has 8 slightly weaker cores (please no-one start the physical/not argument). In single threaded games the i5 therefore has the advantage as they use less cores. In multithreaded games the FX catches up and in some instances performs better. In other multi-threaded apps such as those used for video editing or 3d modeling the FX is ahead. The i7's ivy/haswell would be ahead or on par with that however, but for much more cost.
Anyway, as I said it's pointless and relatively difficult to speculate about what the future will hold. Get what you need for right now and then upgrade in future when you need more power, or overclock! Both CPU's will perform very well and games are more dependent on having a good GPU anyway.
Single-threaded applications run better on the i5, but the i5 has less cores so it can run less active threads simultaneously. The FX-8320 has twice as many cores, so you can do more things at once, or have more running apps. That's not to say that the i5 cannot handle many apps opened, but it won't be as efficient.
Ah, I missed that it wasn't for gaming. Some of what I said however was still relevant.
Honestly, for daily tasks just get a 6300. It will be absolutely great and even good for gaming if you ever feel like it. As ksham has already said the more cores you have available the more things you will be able to run simultaneously.
You really don't even need a 6300 you could get away with something far less powerful. But the 6300 would keep you covered for basic tasks for years.