So pretty much buy whatever you're comfortable with, PC or Mac, take care of it but face the reality that many of these machines are built with planned obsolescence in mind and having to replace it in five years isn't an exception but more the rule?
I miss the days when things lasted longer.
I keep my old macs or sell them, I toss my PCs after about 8years. But then I keep my old truck too. Classic cars get rebuilt to extend their life. Most PCs are not classics.