I think the summary of all the heated debating above is that both can offer different things, but often is a matter of choice. I've used both PC and MACs for design and video - and althought I agree with some of the relliablility issues raised above (with PC), if you know how to properly maintain both they will BOTH work well. But as far as web design is concerned, I would consider this when choosing - more programs available on PC, more people use PC than MAC generally and don't forget that you can get Windows WITH a MAC.... Anyway... food for thought...
Btw.. as another person pointed out.. lets keep to the original thread rather than going off on a APPLE v GATES debate! hehe? don't shoot me please...