For the constant adventurer...Final Fantasy III (read our review)
Anything that says "Final Fantasy" on it will sell. But this old-school RPG is special for an entirely different reason - it's the only one of the million-selling franchise that's never made it to the US before. Now, with a complete graphical overhaul and remastered music, it's an absolute must-play for any and all role-playing fanatics.
With an adventure that lasts more than 30 hours and a fully customizable party of heroes, you're definitely getting your money's worth. Side quests and hidden extras add even more hours to the experience, but know this - RPGs like this were made for the hardcore. Casuals should keep their distance, as FFIII is one of the least-forgiving tales you'll find on any platform.
Second choice: Final Fantasy V