The first Metal Gear on the NES was a decent to good game, but they got much better as the went. Still haven't played a "Trails" game, but the Legend of Heroes series is decades old and the early games weren't that great. Wonder Boy actually started off as Adventure Island, but I like Wonder Boy in Monster World better. And while I know plenty of people who loved Tetris back on the NES, I couldn't get into it until it became Puyo Puyo Tetris. Now it's my favorite multiplayer game on the Switch.
The first Legend of Heroes game was the sixth Dragon Slayer series game. Earlier Dragon Slayer games included Xanadu (which itself had three spinoffs that released in the US, Faxanadu on NES, Xanadu Next on mobiles and PC, and Tokyo Xanadu on Vita), Legacy of the Wizard (Dragon Slayer IV) on NES, and Sorcerian (Dragon Slayer V) on PC. Dragon Slayer: The Legend of Heroes was localized in English on the TG-16 CD but didn't really make a splash there.
Faxanadu and Legacy of the Wizard actually weren't bad games back in the day. For NES games they had a lot going for them. You can actually get Legacy of the Wizard as part of one of the recent Namco collections on Switch. Can't really say about Sorcerian since I never played that one.