Oh look, this thread. Again.
I would suggest using the search function in the red rifles form to find a ton of threads asking this very question - I know I've posted in at least five of them, so they're there.
Short and sweet: Chinese will be unissued. They will look a bit less shiny, but they will preform just as well (occasionally better) than the standard Russian refurb in terms of both accuracy and reliability. ALL Chinese ones will have chrome lined bores, while maybe 95% of the Russian ones will, as they didn't chrome the barrels until 1950, IIRC. This doesn't really matter as one should clean their rifle as soon as possible after shooting corrosive ammo anyway. For first time SKS buyers, I recommend the Chinese one. It's unissued, and you're the first person to use it. It's a great feeling, holding a piece of military history and being the first one to ever shoot it and clean it, being the first one to find out it's quirks and how it groups and what ammo it likes to eat. My first SKS, which was also the first rifle I ever bought, was a Chinese SKS from CanadaAmmo. It's gone through about 11 thousand rounds thus far, with only one malfunction. I would highly recommend CanAm and the Type 56 rifle.
After that, I recommend looking into Russian ones, as there's a whole other set of history there for you to enjoy. Russian's are more collectable, but I can see that changing in 10-15 years time when the Russians have all dried up and the Chinese ones are still around a bit more commonly.
Both will outlast you if you clean them. I however am not as sure that they will outlast this stale topic and the threads that come with it.