Breath of the Wild/Smash Bros are the two bigger titles I have on it.
Mario Odyssey is good. It advertises itself as co-op but I feel like the gameplay for that is a bit lacking.
PKMN sword/shield when they come out
For a good couch co-op try overcooked.
One of my favorite games to play on switch is Rogue Legacy. It isn't an exclusive or anything but it is an old school platformer with procedural dungeons that change every time you die.