I just recently got the two Target exclusive hoth packs and I thought they had some really neat artwork. The "Attack" set in particular, I thought was really cool. On the side of the box they have 3 AT-ATs with a Star Destroyer above them and with a planet behind that. The AT-AT box and Slave I UBP also had some really good artwork.
I have to admit, I hadn't paid a whole lot of attention to the box art until I looked more closely at these hoth packs. You can say what you will about having a clone on the box, but I think Hasbro has created some really nice artwork for thier vehicle packaging. I'm kinda curious who does the actual artwork.