My desktop is Windows XP, my laptop is OS X, my FTP/music/print server is OS X, my number crunching machine is NetBSD. Right, just pointing out that I'm both experienced and not loyal to the death for any brand.
There is a lot of bull flying through this thread.
OK, the right click thing.
Buy a two button USB mouse with a scrollwheel.
My OS X server has a Microsoft Intellimouse Explorer on it (iThink that is what it's called...) It is optical, has two buttons and a scrollwheel. Problem sorted.
Games:
If you are a hardcore gamer, don't buy a mac. It's that simple. I play games, but not heavily. A bit of Warcraft 3 on the mac occasionally, a bit of Doom 3 on the XP machine, but I haven't touched either for a couple of weeks. If you might want to play occasionally, get whatever you want that fits your other needs.
General Software:
What do you do on your PC? The mac will handle word processing, internet use, programming, DTP, design and basically everything the average home user can throw at it. When it comes to specialised tasks, there are things that the Windows PC won't do, will do, and in between (I'm thinking POSIX tools here.) OS X will run POSIX with minor tweaking, and many useful things have been ported already.
Fiddling/tweaking:
Pick up a book on BSD and you will basically learn how to fiddle and tweak with an OS X machine to your hearts content.
I think that covers a lot of the main problems people have with the mac. I'll return to see what else can be thrown at us defenders as a whole
.
A little reminder at the bottom of this post as well, I use OS X, XP, BSD and occasionally linux.