I'm playing Final Fantasy II. I just finished Final Fantasy I. The graphics and mechanics of these games have been enhanced so they're a real treat if you like the old sprite style final fantasy games. Final Fantasy III is also available and they gave it the whole 3D effect treatment, I'm looking forward to that very much.
After the final fantasy games I intend to download Duke Nukem 3D (for a dollar!) and Civilization: Revolutions. Afterwards I don't know what I'll do.