I say for me it's an actual toss up between Playstation 1/2 and GB, I do recall playing more RPG like games on the Playstation 1 and 2 and a few on GB (Original release of Final Fantasy's obviously, but Chrono Cross and Legend of Dragoon come to mind for Playstation; and of course Pokemon, FF Mystic Quest and Dragon Warrior all come to mind for the GB)

To pick one though I would go with Playstation.