I believe that there was RPG Maker 95, 98, 2000, 2003, XP, and VX for the computer, then RPG Maker (1-3) for the PS-PS2, and then there was a Japan-only RPG Maker Advance... And now they're coming out with Action Game Maker. I think that that's all of them, but I can't be sure.
i also agree with you, Jking. it's a good program at the moment, but unusable... and it uses RMXP music. i don't personally like the handling, but that's just personal preference i guess.