A fanfiction to the anime series Tenchi Muyo, and the canonical example than lemons are not necessarily crap. The basic story so far: Tenchi starts sleeping with Ryoko and Ayeka on alternating nights (with their knowledge). The three then have to deal with the emotional chaos this causes. The story contains what I believe is the most truly erotic scene I've ever read, in chapter 10.

Unfortunately, Aikan Muyo is very unfinished, and the author Happosai is lacking time to continue it.