Let's take a look at the actors who portrayed the "Clown Prince of Crime" in celebration for this summer's Suicide Squad:
0:05 Cesar Romero (19661968)
2:24 Jack Nicholson (1989)
4:27 Heath Ledger (2008)
6:32 Jared Leto (2016)

Clips:
Batman (19661968), Batman (1989), The Dark Knight (2008), Suicide Squad Comic Con Trailer (2015)

Rights go to 20th Century Fox and Warner Bros. Pictures. I do not own any of the clips. I made this video for entertainment purposes, not for profit. No copyright intended.