Rance VI and believe it or not I actually wrote a
Monster Article about why I like it more then a mainstream RPG. It's a great game and not that hard to get into even if you don't know much Japanese. Lots of stuff to do as well that makes it well worth the investment. Plus the music is some of the best you are ever going to find in an eroge (at least in my opinion) so you won't be bored while playing it.