Double Dragon 2 on the NES is one of my fave games of all time - Just in case you didn't know the DD2 arcade PCB doesn't have much in common.
I think of it as Double Dragon 1.5. Arcade has 4 missions while the NES has 9 - level design is completely different - and arcade does not have the story cut-scenes, but they do share some of the same characters and bosses. Still a good game but I would rather play DD2 NES.