This is a long shot, because most of you guys don't seem to like amateur stuff. I do. Several years ago I rented a volume of Ed Powers' Lovin Spoonfuls which included a scene that I've never forgotten. It starred a scrawny red-headed amateur who probably never made any other films. She was not pretty --she looked like a real librarian, albeit a very young one. She was very nervous; she'd decided to make a movie because she wanted to see what it was like to get ass-fucked. What made this scene special is that eventually she gets so into it she seems to forget Ed is there (wish I could've forgotten, too) and, while sitting reverse cowgirl on his cock (up her ass), starts frigging herself with a truly fiendish intensity, her tiny freckled body shaking so hard it appears she might simply disintegrate. I've seldom seen a "good" girl lose control so completely on film.
To make matters more difficult, I'm convinced she was not pictured on the box.