Someone on 2ch.net (not me) posted their top 100 favourite eroge songs.
「俺の好きなエロゲソングTOP100の発表です」
See Article: kahouha2jigen.blog.fc2
See Youtube Channel with all 100 songs: youtube.com
[youtube http://www.youtube.com/watch?v=Srf80ERqZ88] Video: Nursery Rhyme OP by Lump of Sugar. Dedicated to someone Pure & Innocent.