sure I'll hop in on this one, so here are my recommendations-
PC-E/NES/SNES/Gamecube or Sega Genesis
Genesis - Dinosaurs for Hire. think contra with 90s comic book humor and dinosaurs. also, it's not as hard as hard corps, so i think it's more fun.
Gamecube - Wario World. No one ever talks about this game, probably because it's kinda easy. but it's a solid 2.5/3d platformer starring the fat man himself. plus, piledrivers everywhere.
PCE - Ai Cho Aniki. i mean,
if that doesn't make you want to play it, you have no soul.
I once watched _joshuaTurbo's kid play it with obvious confusion.