Fore wrote...
UHG, for once I want a hentai where the girl want to have sex, is clear about the fact that she wants to have sex, and enjoys the sex all the way through without ever using the words "no" or "stop". You know what is a turn on for me? The girl I am with being happy and enjoying herself. That never happens in hentai, it always seems like she is miserable and the man makes her feel some pleasure anyway. If there I have missed any like I described, please let me know.
There's soft-core stuff like Futari Ecchi (Step Up Love Story in english) that has in the past left me very entertained because it's sooo cute and sexy at the same time.... however I have to admit there is a distinct lack of what you mentioned out there.
Love Selection is the only hentai(animated) off the top of my head where everyone is willing and wanting it, but that's the very reason I didn't really like it that much... I prefer to put myself in a fantasy with a bit more forceful men. ;)
Oh and remember that Japanese definition of a sexy woman appears to be an "innocent girl", and innocent girls aren't horny and wanting it. They often cry or make little kid noises during sex because that's what appeals to the males.