If you have to debate on whether AMD or Intel is better, follow it on these rules:

AMD is for performance

Intel is for quality

If you plan to play games, go with Intel. If you plan to do anything else, go with AMD. I use AMD and have no problems. Just don't settle on a shitty one like Athlon or Turion. Always go with Phenom.

And the main difference between the i7 and 955 or any quad core is that the i7 has 8 threads where as the 955 or i5 has only 4.