No big deal on the last thread, it was actually more civil than they usually are. Try posting it on the AR side and watch 15 pages of arguements and mud-slinging!
This is a very open ended question, but it comes down to what you are willing to pay, and what you are looking for.
On the bottom end of price and quality you have the Romanian rifles (SAR series) and on the top end you have the Russian, Bulgarian and Yugo models. I will just pick the Romanian SAR models as other people know more about the other rifles.
The SAR-1 is 7.62 X 39, the SAR-2 is the 5.45 X 39, the SAR-3 is 5.56 (.223)
They are great starter rifles. The quality is fine especially on the newer models. But always look at it before you buy, the front sight base can be canted on some.
The stocks are usually laqured quite badly, but with enough sand paper you can turn it into a really nice piece of wood. They function as well as any AK despite not being of the highest quality - the virtue of the AK!
From this gun you can ad K-var stock sets or the RSA trigger or add the origional muzzle break. Or, you can just leave it alone and enjoy it as a no frills simple cheap workhorse.
The SAR-2 in 5.45 is harder to find because I think it is a secret that has just come out. It is far more accurate then the 7.62 X 39, has less recoil and is a more lethal round. Ammo is as cheap as the 7.62, but sometimes harder to find.
I have a Chinese MAK 90 and I really think it is a great shooter. My SA-93 (Bulgarian) has a totally different feal to it, but shoots really nice as well.
In the 5.45, I have two different Romanian models. I have done a lot of building up on these two rifles, but they are as nice as any other AK. With these, the recoil is so light, I can dump a whole 30 round mag. as fast as I can pull the trigger and never move off target by more than a few inches.