I empathise with your problem.
I bought a revision A MacBook and as soon as I got it home noticed the noisy fan and "mooing" that plagued the MacBooks at that time.
Within a few weeks I was having random shutdowns and I, despite my better judgement ignored them because I needed the machine for work and being without it would lose me money.
Six months later and I was having a shutdown daily and problem after problem was arising, however it wasn't until one day when I couldn't get the machine to boot that I finally took it for repair.
I went to the nearest Apple Authorised Service Centre, Micro Anvika on Tottenham Court Road, anticipating this would be faster than booking an appointment at the Apple Store on Regent Street and having it appraised by a genius, I was wrong. I was without the machine for 29 days for a replacement logic board, 30 days later the hard drive died taking with it a months worth of work I hadn't backed up due to losing the backup applications while it was in for repair and not having got round to replacing them.
This time I took it straight to the Apple Store and was told that yes the hard drive had died and I'd have to wait ten days for repair.
I declined to leave the machine with them and instead went home, transferred some money from my savings account and returned later with £1100 in cash to buy a replacement Core 2 Duo MacBook.
I've since sold the CrapBook, as I affectionally named it, on eBay for £250 less than I paid for it from the Apple refurb store ten months ago and have been overwhelmingly impressed with the new model. It's rock solid and what the previous one should have been.
Prior to my MacBook I had an iBook G3 12" from 2002 that was plagued by the failing logic boards, my one had 5 replacements during it's lifetime, and you'd think that I'd have been warned off Apple hardware by now, but, the fact is Apple hardware and software fits my need like no other product on the market. It's not perfect, not by a long shot, but it's what works for what I do.
I work as a designer and write copy for several online publications, no windows or linux solution fits what I want and need like an Apple product and that's why, despite their problems and quibbles I stick with them.
I use a windows machine at work during the day and an Apple machine at home and when on the road, it's not that I don't know windows well enough, I know Windows inside out and backwards, but I don't enjoy using it. Windows is a chore to use, I will have to go and tinker with something or other at least once a week in order to keep things going as they should, not that I don't ever have to tinker with OS X, I do, but it's far less often and something that generally isn't critical to get the job done.
At the end of the day, Apple have been propelled to this god like hardware manufacturer whose products NEVER die, of course that's utter bullshit. All electronic products have their lemons and Apple suffer like every other manufacturer out there. No matter how painful at times my relationship had been with Apple, my experience with Windows and generic x86 hardware has been just as bad if not three times over.
Apple have their flaws, as do Microsoft, HP, Dell and all the other wintel manufacturers.
The point is, and this is what I've been getting to, you, as I have, returned to Apple and OS X without throwing your hands up and returning to Microsoft and it's poor offerings under the Windows umbrella.
Hardware fails, all the time, but it's an equation of whether those hardware failures are worth dealing with for the overall user experience.
That my dear is the question.