I've had a bunch over the years. Some I wish I hadn't sold, but that's another matter.
In general, condition is more important than country of origin. A Chinese in good working order is better than a Russian rellic. Pick up a manual and learn how to do a basic field strip, and do so before you buy. ALWAYS look at the gas system, that's a big place where you may find corrosion issues from improper cleaning after corrosive ammo shooting. Make sure you ask before you strip down a gun you don't own, but if they won't let you do it or do it for you, pass on the deal.
A couple of features that may be important to you. The Yugos are a little heavier than the reast. Not twice as heavy, just a little heavier. The Yugos also are the only ones (I think) that don't have chrome lined barrels. That's good and bad; the non lined can (hypotheticly) be a little more accurate, but not if they get rust in the bore. There are still some "unissued" or "new condition" Yugos around. Don't cheap out. If you get a Yugo, get one of those because it's cheaper than getting a used one and having to fix it.
My opinion of which is "best" is the Russian late refubs. Those were Russian guns refurbished after most any issue associated with using the SKS were understood. They are less collectable than an 'original' rifle, but they have all the fixes and are the best shooters, again that's opinion. The Late refurbs have laminate stocks, two recoul lugs through the stock (plainly visible and the best way to identify them) and black bolt carriers. I only have one SKS now, and it's one of those. Mostly they had new barrels and small parts put in during the refurb process, then weren't really used because the Russians had switched away from the SKS. They are like new guns with storage wear.
The SKS has a known firing pin issue that is readilly treatable. The original prototypes had a firing pin with a spring to hold it back (like the 1911 pistols) In production, the spring was eliminated to save a buck. You can buy a brand new stainless firing pin with a spring for about $20. Without the spring, you will ave to shoot ONLY foreign ammo. The US made ammo has thinner primers and can slam fire in an unmodified SKS. The modified firing pin will work well with both the US and foreign ammo.
Also, take the bolt COMPLETELY apart before you shoot it. Clean, lightly lube and reassemble. Sometimes they have cosmolene in there that can stick the firing pin forward. Very dangerous. Also, clean the trigger group. It's easy and the manual will show you how. People shooting guns full of cosmolene has caused plenty of accidents, don't let it happen to you. The triggers are crappy. There are a couple of gunsmiths around who specialise in SKS trigger jobs. Good part is you send them the trigger group, not the whole rifle. Well worth it for a gun you want to shoot.
The SKS is a great value and an under respected rifle. Where else can you get a semi auto that is as reliable for a price anywhere close? All steel and wood, good gun. Just don't buy one that's rode hard and put up wet, make sure you clean it thoroughly and you should have a rifle that will last longer than your life time.
