I've played way more Pokemon Violet than I have Arceus, but it's not really for any good reason. Arceus is soooo cool and very fun. It does way more 'different' with Pokemon than Violet/Scarlett. Even though Violet/Scarlett are arguably very different from most previous Pokemon games, it still retains a bit more of the classic mechanics. Pretty loosely though. Arceus just has better art design, less whacky performance issues and is very unique and fun.
Non-Exclusives:
Celeste
Castlevania Advance Collection
DOOM 1, 2, 3 + 64. Just really cool that they keep updating these.
Final Fantasy 7, 8, 9, 10, 12
Exclusives:
Part Time UFO
Splatoon 3
Super Mario Maker 2
Mario Party Superstars
Luigi's Mansion 3