Paper Mario for sure.

Super Mario RPG has been basically replaced with Paper Mario. Most who didn't choose Advance Wars has never played through an Advance Wars game.

Mother. Earthbound is one of my favourites RPGs ever.

F-Zero

Go F-Zero. Great franchise. Needs a reboot.
Advance Wars needs to be made. Switch would do wonders for it.

Without a doubt, Ratchet & Clank

F-Zero, Fast Racing is good from a technical standpoint but it isn't the same. One of the things that made F-Zero memorable were the zany characters and speed, Fast Racing gets the speed portion down but the characters despite their limited presence in the overall game helped make that franchise the definitive futuristic racer from F-Zero X onward to the GX/AX games.

Also shout out to Golden Sun, which I think is probably dead now that Nintendo has gained a appreciation for the Xenoblade franchise and the Fire Emblem IP has taken off. Those two plus Mario and Luigi plus the Pokemon games seem to have all other RPG projects pushed to the side for the foreseeable future.

I'd say Golden Sun, though I still have hope for a new installment. Who the heck ends a franchise on a cliffhanger like that??

Golden Sun

Super Mario RPG.