My next computer will be a MAC. I'll have to buy new software - lots of it as I run a business on this PC, but I am totally fed up with PC. The constant updates drive me insane. Windows, Flash, and my security software - all need updating constantly (although I must admit the updates have slowed down a tad, but I'm sure there will a next wave of them coming through). When I talk to my MAC support guy he doesn't have to deal with as many. Not only that but the operating system is just more stable ... it doesn't crash or just *hang* as often.
Yes MAC's cost more up front, but they do last a lot longer.