Intel Core i5 750 2.66GHz vs AMD Phenom II X4 Quad Core 965 Black Edit

It will be certainly more powerful however LGA 1156 is a dead socket and you won't have a reasonable upgrade path. Due to platform considerations i recommend the AMD CPU.
AMD will continue to release CPU's for this platform likely for another year and you also have the option to upgrade to a six core cpu which should help performance in your applications more so than the I5 750.
In fact i would recommend a good AM3 board with the 1090t AMD six core CPU and thats what i would build if you were my customer. The 1090t will be $300 only one hundred more than what you are considering.(http://www.newegg.com/Product/Product.aspx?Item=N82E168...)

I would get the Phenom II X6 1055 before either of those processors.

Don't get the AMD X6 series processors unless your looking for multi-tasking, browsing, and productivity. The hexacore processors are aimed for business and productivity, not for gaming at all... your better off getting the Phenom 965 over any processors stated above... check benchmarks before asking these questions! :0

I was on the edge of pulling the trigger of an i5 750 looking towards an i7 920, then AMD released the hexacores in April or so, and I bought one, and I am very happy I waited.  

It flies through encoding, especially h264, where all 6 cores are used (handbrake is my prog of choice).

The more cores you have, the more options you may have in the future.

i7 920 or better yet i7 930

AMD Phenom II X6 Six Core 1055T 2.80GHz is the winner, its Cheaper and did not know Intel will be changing the sockets so soon! Thanks guys great help.