I think RRoD was the major difference in the end. If their console wasn't an unreliable piece of shit I would still own one. Mine died on me 3 times, buying a 360 is essentially buying a ticking time bomb full of games that have a superior PC version (where FPS will always be better).
It's really too bad because MS would have done a lot better than the PS3 if it weren't for that giant red warning hanging over their head.
3rd Party Wall of Shame
http://www.nintendoworldreport.com/forums/index.php?topic=30478.msg581036#msg581036