Another advantage of AMD over Intel, standard range of processors, is the temperature. AMD do run comparatively cooler.
The two companies have diversified a bit, and Intel have probably lost the lead for innovation, certainly temperature has held them back. Intel were first to the market with hyperthreading allows the processor to emulate two processors in one, although not that much software really takes advantage of that, yet. AMD have hit back with dual core, which is in fact two proper CPUs in one, not just an emulation, altough Intel are now just starting to work through their range also introducing dual core, whilst also having hyperthreading capabilities - two full, plus two emulated processors on one CPU
These intel processors are very new to the market though, not yet readily available, in all ranges (but eyeing up a pair of dual core Zeons for a new office server
)
However Intel do probably have the lead for mobile (laptop) processors - the Pentium M range.
Realistically, AMD tend to be a tad cheaper for similar performance, but choice of processor, needs to be matched to motherboard, quantity and type of memory, and hard disk types, even graphics card, for a balanced system. It depends what you are wanting your PC to do, but no point having a top end CPU, with next to no memory, and a slow HD.