The first thing that sprang to mind was fanfiction, strengthened when you said you were a slasher. XD But there are plenty of books which have good or at least decent sex scenes. Tanith Lee is very good, I agree with another comment up there. Neil Gaiman has very few explicit ones, but he is great at everything he does. Ellen Kushner is awesome as well, though her bits of sexing 'fade to black' and you always keep wanting to see the rest (which is good, really, because you have enough 'heat' without TMI). :3

It's great to laugh at sex scenes, though. I tend to do the same when they go all over-the-top on me. But what makes it 'good' even if the description itself isn't 'all that much' is that it actually has a meaning for either the reader or the character or the story - something, because otherwise the scene can be aside from bad, pointless. *points at LKH*