Well as the names suggest, hardtype is the more difficult of the two. It depends on your own skill level and how much of a challenge you want, because hardtype is difficult. Off the top of my head... um... all monsters are stronger, you cant by Ethers until very very late in the game (as opposed to easy where they're in every shop from the very beginning)... etc, etc. It's really your call, I'd recommend easytype to start out with if you're newer to RPGs, hard if you're a pro.