Of the games listed, I would have to say Mario RPG. That was really impressive at the time, coming out so late in the SNES' lifespan and being so engaging. Sure, it was a bit on the easy side, but I'd love to see the same cast of playable characters reunite for another adventure - with a different graphic style than Paper Mario. Which is a lot of fun, but just not the same vibe.
That said, I voted for 'Other'. I doubt anyone would agree, as it was a bit of a flop - but I'd really like to see them take a stab at remaking or re-imagining Secret of Evermore, from 1995. It lacked the quirkiness of Japanese titles, but I thought it was a real creative spin on the genre to move the setting to the 20th century United States, arm the character with a bazooka and a dog, throw in some mad scientist elements. With some improvements, I think it could make for a really neat game.