There is no definitive answer as to which is better or worse, it all depends on the users own personal needs, budget etc.
I can explain some of the differences:
- AMD CPUs have a memory controller located within the CPU, which means the CPU can communicate directly with the memory without having to pass through the north bridge (= chipset). On an Intel platform, the memory controller is located in the north bridge, which means the CPU <-> memory data has to pass through the FSB and NB. This limits memory bandwidth and increases latencies.
- Until Core 2 was released in 2006, AMD held the performance crown for a long time. (Un)fortunately, the tables have turned, and the highest performance CPUs now have the Intel name on them. That's not to say AMD don't have any high end products, but if you want THE best of the best, you will have to go with Intel.
- Ummm, I'm running out of ideas here...
Intel chips also run cooler than AMD chips.
This is thrown around a lot, I really don't know who started it but it's not true.