Batman easily has the most intriguing and three-dimensional villains of any single hero. With Batman we draw a comparison between Batman and the crazies he's locking up and wonder whether he's really all that much different from them. We have to wonder if Bruce Wayne's obsessions might make him fit for Arkham Asylum just as much as Jonathan Crane's obsession with fear or Edward Nigma's obsession with riddles. We ask ourselves whether or not a sane, well adjusted man would dress up like a bat and chase killer clowns across rooftops in the middle of the night.
So, yes I'd say Batman has the best gallery in DC, perhaps the best in the Big Two. They serve a purpose greater than attempting world domination so the hero can save the day.
Also, super powers or not, the Joker has killed or maimed more people face-to-face than most super-villains could ever hope to.