Honestly, I just want two (edit: three) things:
- Game Boy/Color games with Super Game Boy enhancements added to all OG GB titles that didn't get them already
- Game Boy Advance games
- Better third-party gets (Final Fantasy, Chrono Trigger, Super Mario RPG, LucasArts, Disney licensed games, etc.)
I don't expect N64 or GameCube games to ever be part of the subscription.
N64 games would either require rework so they function as well as Mario 64 does on 3D All-Stars, or wireless N64 controllers which seems like a "not gonna happen" situation.
GameCube games could just be emulated a la Sunshine on 3D All-Stars, but the big download sizes would mean they'd have to expose them differently as part of the subscription which I don't think is super likely.
The far more interesting prospect for me is whether they release new online games this year. Last year was I think just Animal Crossing, Clubhouse Games, and Mario 35? They need a new competitive online title for this year imo.