Batman (1989)
Batman Returns (1992)
Batman: The Animated Series (1992)
Tim Burton's dark movies were the best. If you love Tim Burton, do yourself a favor and watch a gem of a cartoon. Batman: TAS ran for 4 seasons.
I don't remember if The New Batman Adventures (1997) and Batman Beyond (1999) were equally dark.
I used to watch "Batman: The Animated Series" as a kid. Recently I decided to watch the entire series for nostalgia, and I was impressed by how good it actually was.
As for "Batman Returns", here's what I wrote on "The Dark Knight" board:
Topic: Not the best Batman movie.
This is probably the best movie where Batman appears in, but if we're talking about nailing down the tone, the music, Gotham City, costume, pretty much how Batman should be, I'd say "Batman Returns" is the actual best Batman film. That film is the true essence of Batman.