I've seen the same thread hundreds of times, and my answer is the same: I like Mac's
Mac does the same thing AMD do, they make their CPU's with lower frequencies but they perform better than CPU's with higher frequencies. a single 1.6GHZ G5 outperforms a 3.2GHZ Pentium 4. the next one up is a dual 1.8GHZ, which owns a 3.4, then there's the dual 2.0 and dual 2.5
they have just so much power. I like AMD also for the fact that they know better than to just clock their CPU's higher.
Mac's are better for video and photo editing, whether or not you think so, it is their software which puts them ahead in video and images.
Mac OS X is not only very stable, and is not only easy to use. the advanced Mac user will still like OS X. it's not just some n00b OS, but has a wide range of advanced features and customisations similar to which Windows has, except Windows lets you delete system files and wreck your system, when OS X has a limit to what you do, and this limit is not very restricting at all. it just restricts you from wrecking the system.
it is entirely possible to upgrade a G5 nowadays. you can put in more of HDD's (including IDE and SATA) or more RAM, up to 8GB - you can stick in Corsair's really low latency RAM, or even stick in a 6800 video card if you wanted.
Mac's are not crap in gaming either, in fact here's something ironic: Halo (a Microsoft product) runs 3 times faster on Mac hardware