I also like Duck, You Sucker although it sounded weird at first but it's the title I've been accustomed to. The other two titles are also cool but not as cool as DYS.
Thanks for the welcome. I came to this part of the board after reading your post in the 8-Disc DVD thread.I think it also keeps growing on you. I keep saying "Duck, You Suckers!" in my head because I think it's great the way Juan says it as he frees the prisoners.
Giu la testa is definitely the best title. I honestly think all of the English language titles are atrocious, but I find "Fistful of Dynamite" to be the least obnoxious. "Duck You Sucker" sounds like a blaxploitation film; given the movie's serious pretensions, it's hard to take it seriously with a title like that. "Once Upon a Time in the Revolution" just rubs me the wrong way, dunno why.