Nexides

I initially started enjoying this because Light was completely dominating L, and L was just so virginal and inexperienced and totally falling for it.

And then I got to the twist, and it was hilarious and awesome. Years later, I still re-read this fic.

Some very nice domination, and deals with sex being kind of new for Adult Link.

Just GLaDOS being pointlessly cruel towards Chell. Also, I can just imagine the way she would say her final line in the fic, and it's hilariously awesome.