A good story, fun characters, an interesting world with facisnating world building. A fantastic battle system. It's a shame Cassette Beasts didn't get as much hype as Palworld is getting.
Not to shit on Palworld or anything, I just feel that half the attention it's getting is a little ... unearned...
I like both 2D and 3D if they're made with heart. Hell, Metal Slug is one of my favourite games because of the sprite art. But if you mean just Pokemon, it depends on the gen.