The top of the line AMD CPU at the moment is the FX 8350 which is a 8 core "Vishera" processor. It retails for around $190.
The top of the line Intel CPU at the moment is probably their i7 3970X Extreme Edition which features 6 cores but retails for a hefty $1,100.
See the price difference?
An Intel CPU that you could compare with AMD's FX 8350 would be the quad core i5 3470K which is worth around $210.
(Intel is always going to be more expensive than AMD)
Now i bet you're saying "BUT AMD HAS 8 CORES AND INTEL ONLY HAS 4 CORES - AMD HAS TO BE BETTER"
Wrong. That is a dumb thing to say these days.
Intel's architecture is 100 times better than AMD, and while most modern applications these days are suited for multi threading - you will get a better performance on 'legacy' programs that only utilize a single core with the i5. Due to their architecture and output per core being much more than the AMD.
Gaming Wise, if you want to save the $20 the AMD FX 8350 is fine and beats the i5 3470K in SOME Areas. And if you overclock the FX 8350 it'll do even better.
BUT.... (there is always a but)
If you pay the extra $120 you can upgrade yourself to the Intel 3770k - which is pretty much the top of the line price/performance cpu out on the market at the moment.
This baby will keep your pc running for years to come, it overclocks well and the only cpu's that beat it are Intels Hexa core 3930k and 3970k ($500 and $1,100 respectively)
The conclusion is.
AMD = Cheap Gaming, Good multi core performance.
Intel = Extreme Gaming, Good all round performance, Future proof, Quality build.