I'd have to say the Pahlavan one, followed closely by the ... err... oh wait, the Casse use wagons instead of actual chariots. Yeah, the Pahlavan one.

The Baktrian one is nice as well, but I'm not a fan of face masks.

As for my least favorite, probably the Hetairoi. They're so boring, I mean how many times haven't you seen something Greek? and they're all identical, and there's tons of family members everywhere, and ugh...