Well, if you want eroge that has great music, you could look into the titles that Ryu Umemoto composed for. Not only is the music highly regarded, but the games are too (YU-NO, Eve burst error, etc.) Here's an article by a friend of mine about YU-NO: http://www.hardcoregaming101.net/yuno/yuno.htm

And while I'm linking to HG101, you could give True Love a try: http://www.hardcoregaming101.net/truelove/truelove.htm

There's nothing especially remarkable about True Love, it's basically Tokimeki Memorial with sex, but given its historical impact for the genre, it's sort of seen as the quintessential hentai game in the US.