As always, it depends. I don't buy PC hardware purely based on the brand or name stamped onto the item... I wanted the best performance and was willing to spend just a little more to get it. So I went with a Core i7 920 + compatible platform and clocked it to 4.2GHz for daily use.
I'm extremely happy with my processor, I wasn't expecting 100% stability for a 2.66GHz -> 4.20GHz overclock at voltages and temps I'd consider safe, but it purrs along fine and doesn't get hot under normal loads. (LinX / Linpack is another matter).
AMD doesn't offer the fatest chips currently but they do compete by offering better price/performance ratios... ie it's cheaper to build a system with them than an equivalent performing Intel system in some cases. Their just launched Athlon II X2 is a good example, it's better than the Core 2 Duo E6300 it competes against. AMD motherboards also tend to just cost less as well.
I wish AMD could get back into the performance game and take back the performance crown... the competition they brought about can only benefit the consumer.