Ducktales is a masterpiece.
Teenage Mutant Ninja Turtles is a bizarre ordeal, but it's a touchstone, and you can at least get to the dam and recognize why a lot of people at-the-time also stopped at the dam. The music slaps.
Mega Mans - 1 is a fascinating relic made better by savestates, 2 is a Nintendo-hard pinnacle everyone glazes, 3 is literally an unfinished beta, 4 is a solid but unremarkable sequel, 5 has killer music but meh difficulty, and 6 is just kinda weird.
Batman is celebrated, but I haven't played it personally.
Kirby's Adventure is a solid entry in a long and weird franchise where basically all of the platformers are rightly celebrated.
Wario's Woods is probably better on SNES.
Bram Stoker's Dracula is worth a go. It's not amazing, but it's pretty good for a licensed movie affair.
There's a surprisingly good port of Elite that was never commercially released but is widely available.
Also I made a first-person shooter that's reasonably good.