I hate to play Devil's Advocate, but I'm a long-time PC and Mac owner. From my personal perspective, and the perspectives of the people who I support on a daily basis who own Macs and/or PCs, the crashy, unstable PC is something that sort of got left behind over a decade ago.
If you own a relatively modern (say, post-2006) PC, and it is crashing and unstable, the vast majority of the time it can be tracked down to (a) hardware problems, (b) virus (tho this is rare) or (c) user error - by this I mean filling up the hard drive, trying to run too much (virtualization on 1GB RAM yeeeah!) or letting the fan vents get clogged with cat hair and dirt. It's easy to throw around "oh Windows sucks, Dell sucks, whatever" but the last time PCs were basically "unstable" was right around OS X 10.0, which nobody will accuse of being stable or fast.
And FYI, Macs, even expensive Retinas, do get bad hardware once a in a while. My client is working on a service contract with two local Apple stores to deal with some of the slightly-out-of-AppleCare machines they have with glitchy screens and trackpads.