Amiga Golden Axe was pretty darn close to the arcade version. Dunno what drugs the people who say otherwise are on.
Running both side by side on my amiga and megadrive and both are better in some ways. Amiga version is fullscreen, megadrive isnt. Graphics are pretty equal, amiga versions being a bit cleaner while megadrive version is a bit pale and washed out, but having a few details at times thats not in amiga version. Amiga sfx are better, but tunes are a bit muffled.
Gameplay wise both are much on par, but both slightly different to the arcade parent (mix the 2 and its pretty much right).
I cant help but feel nostalgia, and the media of the time plays a bit part in peoples perceptions.
Double Dragon2 I enjoyed as well. Fun beat 'em up, but plays a bit differently to the arcade version. It's a lot easier for starters
All up I'd say its a tough call. As conversion factor goes theyre both a good 7.5-8 out of 10. As games, maybe 7-7.5.
Im gonna go with Golden Axe, soley 'cos of how much I played it in the arcades back in the day vs. DD2. DD1 I played a lot when it was the "latest and greatest" thing, but DD2 was too similar, so didnt receive as many 20c coins as its predecessor (still enough to complete it a few times though).