if its an i7 you seek a match for, than there is none.
However, just because an i7 is better for gaming doesn't mean it's necessarily the best processor for the task.
If you run a lot of multi threaded apps, a long with gaming. I suggest a fx 8150 with an am3+ and overclocking that bad boy as high as you can. Not only will you not have any issues gaming, you will still have a fast processor for much less.
amd have nothing that compares directly. due to the fact amd have to sell em cheaper, run em faster and add more cores just to keep in the same ball park...
the situation as it now stands isnt good for amd or us. if you take price out of the equation then the best fx is comparable to the first gen higher end i5/i7. bulldozer needs some optimization and it wont be easy for them to keep up never mind gain ground.
as far as 2011 socket cpu's theres nothing in the amd arsenal that can match the higher end intel parts. its sad but true. and that means that we the user will not get the performance gains as cheaply as we did in the past...
haswell for instance is likely to top $300-$450 for the bottom of the line cpu if amd cant bring something to the table with pile-driver. the 3930 is a prime example of the inflated prices of the new socket and cpu.
Well in a few weeks we will see if Piledriver (Through the L3/Core crippled Trinity APU) will be able to close the gap up a bit hopefully more than it was widened (not very much (3.7% with Ivy)). But as of now depending on your usage the only Viable AMD processors are the FX8150 and Phenom II 980. Depending on what you play they can perform similarly to the i5 2500K but some games will show a significant gap.