I'm not big into manufactured collectibles (variants) and am more into 1st appearances. I think the play is to invest in things that haven't been adapted to tv/movies yet and hold onto them until they are. I have a pretty good eye for these things because unlike a lot of speculators, I read the stories so I know what's good and would easily translate to another medium. Some of my favorites are: Fallen Angel #1, Resurrection Man #1, 52 #11, Major Bummer #1, Planetary Preview/Planetary #1, Violent Messiahs #1, and Hexed #1.