From the top of my head:
Mega Man 5
Mega Man 6
Kirby's Adventure
Castlevania 3 (while not graphics related, the Famicom version benefits from having better sound/music quality)
Battletoads
Little Samson
Honoo no Doukyuuji - Dodge Danpei
"Just for comparison Uncharted 4 was 20x bigger than Splatoon 2. This shows the huge difference between Sony's first-party games and Nintendo's first-party games."