Everything that doesn't go for realism ages a lot better, but realism is important in some games, like the ones with lots of facial expression.
As for personal preference, I think hand-drawn sprites (Ori and the Blind Forest, Rayman Legends or KOF XIII) are probably my favourite, but then there are also things like The Vanishing of Ethan Carter, which is like a realistic 3D painting.
Can I vote for "everything as long as it's well designed"?