I would definitely buy Guts, Caska, Griffith, and Zodd the Imortal from Berserk if I saw them.
Others come mostly from novels, so they would be difficult to pull off. The Gunslinger from the Dark Tower series, Paul Atreides, a Fremen warrior, a Sardaukar warrior, and Feyd-Rautha Harkonnen from Dune.
Also if someone made action figures of all the principle Æsir and Vanir gods and goddesses I would have to buy them.
The Kari action figure from Mythbusters might be nice. After aw hile you would have to blow it up.
I’m thinking Ann Coulter with a Medusa hairdo, holding her own head, wearing a black minidress. Spontaneously combusts when you read the New York Times editorial page to it.
I would love poseable action figures of the Ankh Morpork City Watch, and other principle Discworld characters. Picture it: An Unseen University Library Playset (Librarian sold seperately); a Patrician’s Palace Playset, complete with Scorpion Pit; Pseudopolis Yard, with Igor’s Laboratory in the basement.
It would be awesome.