Your inviting a fan-boy flame war here, just warning you. This type of question gets asked every single day here.
It comes down to budget vs. what you want to do with your computer. Do you *only* game and have a high budget? Get the i5 then. Do you do a little of everything on top of gaming and have a more modest budget? Get the 6300.
lastest review by toms. just ignore that hafjiur guy, he advised someone to buy a new intel cpu, but it was clear that his fx8350 got thermal throttled due to reaching 70C and he just kept on spamming the thread while everyone elso tried to solve his cooling issue.
CooLWoLF has it nailed. If you're going for price erformance, AMD wins every time. If it's ONLY gaming performance and/or intel-orientated (I.E, uses the biased intel compiler) and/or price is of no concern, intel wins.
This proves that amd fx is entry level cpu for games as they like higher ipc and memory bandwidth.
lol just look at that toms review, most games are GPU bottlenecked (!!!) so there is no difference between 75% of the cpus, and then there are skyrim and sc2, which are known for performing bad on fx cpus due to only utilising 2 threads. sure the i3 will win in the, if this 2 games were changed to crysis 3 and bf3, the fx would blow away the i3.
YOU CAN ALWAYS FIND REVIEWS WERE SOMETHING PERFORMS WORSE THAN SOMETHING ELSE, you just need to pick the right one.
ugh. you'll get the fanboys shortly, one already popped up, so good luck getting good advice.
Here is my 2 cents. in 99% of your daily tasks you won't be able to tell the difference between a 6300/8320 and a i3/i5/i7 of ANY make or model. Unless the 2 possible computers are sitting at your desk side by side its almost impossible to tell which processor is in which box. This makes the FX lineup an acceptible cpu when you're building with a budget, as you can save money on the cpu and spend it on other parts.
That said, if you're rolling with a computer monitor with better then 60hz refresh rate, at a larger then 1080p resolution, or you simply demand all games now and in the imediate future to play maxed everything, and budget is no concern, you really should go with the intel.
If you're working with a $500-$800 budget go with the AMD... 800-1000 is sorta a no man's land when it sometimes makes sense to go AMD sometimes intel, but around $1000 it stops making sense to go with ANY amd chip (and if your budget is less then $500, it starts to make sense to go with a pentium g series cpu, or an amd apu... depends on the budget and build, but its no longer cut and dry to go AMD at that point) .
By way of perspective, I have two systems that can run anything/everything I have. One has an i5-3570K, and the other has a Phenom II 970BE. The FX-6300 you are considering offers performance somewhere between them, probably closer to the latter. In any case, both CPUs run all my stuff. Games are more dependent on the video card, so depending on how those are switched around, my games run well on either system. That said, the i5 runs them a little faster, and a little smoother. It isn't extreme, but I can tell the difference. You won't suffer with either one, but consistent with benchmark charts, the i5 is undeniably faster, and it uses less power for the speed it offers.
Some notes of caution though, especially if you're on a budget. There are a lot of cheap AM3+ motherboards out there, with a wide variety of problems. You'll find a lot of older 700-series boards with 900-series names. They typically lack modern interfaces, such as SATA 6Gb/s and USB3.0. You'll even find some old nVidia chipsets, that in addition, run their hypertransport buss as slowly as 1000MT/s (2600MT/s is common on a modern board). These, and some of the cheap true 970-series boards (*cough* MSI *cough*) also have weak VRMs, that cannot overclock, and will likely pop if you try. AMD's FX chips really need to be overclocked to get anywhere near their performance potential, and that means you can't go too cheap on the motherboard, and you'll need an aftermarket cooler (another $30+). On a really tight budget, IMO, you'd do better getting a relatively inexpensive H77 board and an i3; you can always upgrade it to an i5 later.