macbook 13'' mid 2010 2.66 GHz Intel Core 2 Duo
yup mine is still running as well, although i had to put in an SSD, since my original HD was about to go down soon...it became very slow and i had to reinstall too often. i also upgraded to 8 gigs of ram at that time. mostly because of the SSD my lap is like brand new (not exaggerating). it will run another 3 years easily i guess.
(only thing bad about that is, i can't stare at a retina display for that time

)
oh and i'm a heavy user, it's actually on 24/7, doing all kinds of stuff. it brought me through my bachelor studies and is now fulfilling its duty during my masters program. even gaming is okay, it ran WoW until cataclysm times, and now has to play games like Trine 1/2 from time to time, no problems. even though it is far from a gaming machine^^
painting in sketchbook / pixelmator with an old intuos3, is also a cool experience every single time. and watching movies, well it's a 13'' screen, but when it's sitting on my lap, it's good enough
and battery is still up to around 88% of the design capacity (sometimes goes up to 90, lowest up to now was 82), after about 1000 loading cycles (pretty crazy if you ask me. i actually fear this one will die first in this awesome system)
ps.: running yosemite