Since owning my MBP from 2007, I never had any major problems with the computer.
The ONLY time I had a real problem was when a couple months ago, in a rare case of defects, my model computer had a defective Nvidia graphics card that caused my computer screen to not work but the computer was still fully functional. Alittle research on the Apple forums and a call to their customer support, and finally a visit to the Apple genius bar in my area confirmed this defect and they fixed my computer for free! I was NOT on warranty either, they made a guarantee any machines of my kind with this problem was a defect and will therefore be repaired fully for free.
I was Mac-less for a good week... depressing too because this was an intensive time for me in college and I worked off of a crappy PC that was virus paradise. Haha but opening my MBP in the mailed box was a heavenly feeling 😛
But other than that problem, I have had NO real issues. Only crashed the computer twice in it's lifetime. Only problems that risen from my MBP is from third party hardware, like when I installed a WD Scorpio Blue 500GB in my computer, I experienced some lagging. A little hdapm solution fixed that real quick though. My MBP couldn't be anymore healthier!