My choice is easy. Dynastic hero. It is my third favorite Action/RPG of all time next to Landstalker and Secret of Mana. I have a long history with the Wonderboy games. Played Adventure Island growing up and Wonder Boy in Monster Land on SMS. Wonder Boy in Monster World was my favorite Genesis game in the early history of the console. I played the heck out of that game. When I first started collecting Turbo Grafx in 1998 I picked up a English copy of Dynastic Hero which even back then cost me I think a little over $100.00 from a private collector. It was incredibly hard to find back then. I waited 6 months checking eBay every day and lucked out cause my friend had connections with a turbo collector/modder.
The only downside to Dynastic Hero is that it is so much easier that the genesis version. But is has excellent music, amazing graphics, and is just plain fun!
I love all the other games listed too. But I realize Nintendo isn't the holy grail of video game design, or originality for that matter.