G&G and Real Sword.
There are plenty of well functioning AKs (in fact, it's hard to find a non-reliable AK). When you say "best," I'm including show-quality aesthetics and building materials. I assume you want a real wood stock (and yes, the Echo1 was not included for a reason) and pretty external build as well as a solid gearbox and inner workings.
G&G has more options to choose from, and they're one of my favorite brands (unless I'm buying an M4/M16) of manufacturers.