I have RPG Maker for PSX, RPG Maker 2 for PS2, and RPG Maker 2k for the PC. RPG Maker 1 and RPG Maker 2k are both designed to create games with SNES-like graphics. RM2k was good - because it is on PC, you are able to import an endless amount of custom characters, sounds, songs, and what not. The RM for PSX was good, considering the limitations it had. It was very easy to use, very intuitive, and a lot of fun. It, too, created games with SNES-like graphics. The amount of characters was a bit small, and you couldn't really import anything. However, despite that, it was still a lot of fun to use.
RM2, for PS2, is considerably harder to use. It makes RPG's that use 3d characters, maps, etc. There are a lot more variables to consider when making each character and map in this RM, but getting good at making RPG's on it can allow you to make some pretty neat RPG's. I'd recommend picking up the strategy guide for it (it's more of a tutorial book/reference book), it'll really help out.
I know there were a few other PC RPG makers, but the fact that you cannot buy them in North America, and the fact that they aren't written in English doesn't exactly inspire me to seek them out.