There's a shit ton of threads on this topic, but I always post the same thing. . . Double Dragon II SCD for PCE is a fantastic import. Just kind of getting pricy unfortunately
I was critical of Double Dragon II SCD when I initially got it, but I've been loving it more and more over the years. It started with me falling in love with the soundtrack....but that's a tale for another thread...
The most common complaint I hear about the game, and the series as a whole, is the platforming elements later in the game. They're definitely hard and take some practice and patience, but with a little due diligence anyone can get past them.
And that soundtrack though...
I beat Double Dragon II (NES, fantastic game) so I was OK, but I can see folks forgetting frustrated at several points in the game.
Soundtrack....
Other than the PCE port, the original NES trilogy really can't be beat as far Double Dragon games go, and I've beaten damn near every console version released (and holy hell are there a lot of them) except for:
Double Dragon on Genesis (shit unlicensed port of the original arcade classic),
Double Dragon II on Japanese Mega Drive (shit port of the arcade sequel that is rare, expensive, and not worth the $100+ price tag), and
Double Dragon III on Genesis (see a pattern forming here?)
Even though I have played and completed them, I don't really count Double Dragon V or the Neo Geo Double Dragon (based off that hilariously bad movie from the 90s) as part of the "classic" series of Double Dragon.
And just for shits and gigs: