Yes, I know this question is asked a lot but it's fun. They can be heroes or villains. My top ten:
Batman
Tim Drake
Cassandra Cain
Shiva
John Stewart
Mister Miracle/Big Barda (yes, they are a pair)
Robin (Damian Wayne)
Catwoman
Jay Garrick
Saturn Girl
It's really hard because there are several LOSH characters that I would include if this list was top 20.