I have 2 office/industrial-grade HP microtowers running Win-7 Pro x64/SP1 since 6/09, with zero burps/farts/fails. Maybe the exceptions, but I always buy higher-grade/upper-level machines. Pays-off in the long run.
All my home PC's (six of them across the family) are home-built using components I researched and selected. The newest PC being an 8 core AMD FX-8350 with 32gb of ram. Two are my kids gaming machines (both AMD 8320's) with high-end graphic cards and SSD's.
The remaining three machines are 2 Intel Core 2 Quads running at 2.4ghz (both at least 7 years old< used to run some things around the house and my amateur radio station, and the last is an Intel i5 that's at least 5 years old.
Not a single component failure of any of them.
If you build something to last -- it will. When you use commodity parts (junk) like Dell, HP, Gateway, Asus, Lenovo, etc.. you can bet they're not going to last.
If you typically buy “higher-grade/upper-level machines”, then you are doing what a lot of Apple/Mac buyers are doing - seeking better hardware - its not always the OS that is the first attraction.
Apple tends towards being a bit more picky on what hardware they use in their machines... and it pays off in longer average time in service.