wow you guys are scared

Personally, I'm mostly a Batman fan, so I'll have to go with Batman, and the Scarecrow :)

Batman, Robin(Dick) and Robin(Tim) NightWing , Kid Flash, Beast Boy, SuperBoy, and Zartanna.

My favorite heroes are Hawkgirl, Miss Martian, Supergirl, Blue beetle, Flash, Zatanna, and Aqualad.
My favorite villians are Tigress, Cheshire, icicle Jr, Harley Quinn, and the Terror Twins

Literally too many to count. My favourite superhero above all is probably Superman, mostly through All Star Superman, Birthright, Red Son and American Alien (though, conceptually, I just find Wonder Woman fascinating and I really hope that more is done with her, though I personally love Brian Azzarello's New 52 run). I mostly adore the weird and absurd characters, like Danny the Street (literally, a living transvestite street who is also a superhero), B'wana Beast (who has the best superpower EVER, get him in a movie WB!) and Detective Chimp (Sherlock Holmes as a monkey). My favourite super villain is Lex Luthor, hands down. So complex and yet so simple in what he wants; to kill Superman. Just read Brian Azzarello's 'Luthor' and Paul Cornell's incredible 'Black Rings' saga for why he is the best DC villain ever! I also have a real soft spot for The Penguin.