Romanian AK's are going to be the most common ones you can find. However, even within that, there are some that are considered "better" than others. For the most part though, I just stick to foreign receivers and barrels as the basic "want" that I have in an AK. All properly built AK's will shoot about the same. More money does not instantly get you a better rifle on this side. A lot of rifles are higher value due to rarity, or collector's value, or how pretty the finish is, or what type of stock it has.
For the most part, I would say that almost any Romanian built AK, from Cugir in Romania (not some kit build by unknown guy with a garage) will be about the best "first" AK you could buy. They are everything an AK should be. They function, and shoot where you aim. Sometimes they aren't the prettiest, but they work.