So here is my perspective as a gamer and a scientist.
I was a windows user for the longest time, about 15 years. I switched to Macs early in my degree. I currently use both a Macbook Pro and a windows desktop. I think that people are too keen to stratify into Low End users and High end users. Midlevel users are forgotten.
Macs and PCs are very good for Low end users these days...people who want to use their computer for communications and doing their coursework. Platform is down to preference there.
Mid Level users, people who want to run a bit more stuff, maybe a bit of development work are again quite well server by both, but I would lean towards PC on this, just on a cost basis.
For High End user, the Mac is the clear choice. The UNIX underpinnings really give it the edge in interfacing with stuff across networks, using the command line and so on. I find Windows a lot more clunky for this. Plus, like with design disciplines, you are more likely to find software that won't work on Windows than you are to find software that won't work on Macs and Linux (because of their shared heritage). It's really just about the community that is developing all this stuff.
As for Gaming...yep Windows takes it, but then again, I didn't enjoy PC gaming. That's not that it's inherently flawed, but developers know these days that the lucrative markets are the consoles, so games get developed for that with PC as much more of an afterthought.
Consider your discipline, and what everyone else is using. I think that people who are saying that Macs are for low-level users are remarkably ignorant, and will probably eat their words if they find themselves working in science.