Ys Book I & II is really a must-play if you're even a little bit of an RPG fan. Consider the fact it was originally released in 1989 and then look at its features - CD-quality music, voice acting, anime cutscenes (There's not too much animation in them, it's mostly still images), and most obviously - The fact that it is basically two games in one! Many people say that the game was 5 or 6 years ahead of its time, and they're completely right.
Coupled with the release of Samurai Shodown II on Monday, we think this is one of the best weeks the US has ever had. Not downloading either game is doing yourself a huge disservice!