OK, so there is one that I always remember:

I'm in college and just started dating a girl I had been chasing since I first saw her walking across campus several months earlier. I was skipping class on a sunny, cool, early morning and was half asleep when I heard the front door open. It was between summer and fall and I had left the windows open in my bedroom the night before, and it was a chilly (although a bright and sunny) morning and I was curled up in extra blankets, sleeping in late, and loving the lazy life of a college student on a beautiful early fall morning.

My girlfriend, just back from an early class, walks into my bedroom, kicks off her shoes and starts to get undressed without saying a word as I peak out from under my covers through one bloodshot eye with morning wood that is only getting harder by the second as I watch her get nekkid.

She crawls into bed, straddles me like a nymphomaniac cowgirl, rubs up and down against my dick with her crotch for a few seconds before sliding it inside and begins rocking her hips back and forth with the most intense and serious look on her pretty face. I am completely hypnotized staring up at her as her eyes roll back, and I put my arm around her back and pull her close, and suck her on her perfect, perky 20 year old tits. Then, I grab a handful of ass with my right hand (with my finger tips just feeling the wetness of the edge of her vagina and rim of her asshole) and tighten my left arm around her waist pulling her into me and start to thrust back.

After a few minutes of this I had an orgasm that was the most intense I have ever felt. It tingled up my spine and curled my toes. I had never felt anything like it before or since.

I don't think she ever said anything to me (or if she did, I don't remember it) and we fell asleep for about another hour or two and got up for lunch and I went to class.

I'd sell my soul to the devil for another one like that.