An intelligent movie recommendations system, anyone?

I’m looking for a website that can recommend appropriate movies for me to watch, both in the “you will most probably like this one based on your current taste” sense, and in the “it may be interesting for you to explore and give this one a try” one.

I have a pretty strong opinion on how it should work: I feed it a long list (as complete as possible) of movies I’ve watched over the years, with timestamps if available, and the system gives me in return a subset of them for me to rate. That is, the system performs an analysis on the input, and determines what additional information it needs in order to form a picture of myself as a movie watcher. And by “rating” I don’t mean just assigning a single numeric score, but expressing opinion on various relevant aspects: how much did you enjoy it? How badly do you want to see similar films? Did you feel uneasy with the level of violence / nudity / other, or rather on the contrary? To name a few.

I’m very disappointed that all movie recommendations sites I can find require for me to choose which movies to rate, and just give me a numeric scale to do so. Not only I’m finding it a daunting task deciding what to rate, but I also have the feeling it’ll result in a biased profile, and that a single numeric scale can’t be enough to reflect all the aspects in a person’s movie personality.

So far, the most promising site I’ve found is MovieLens, which is developed by a research group at the University of Minnesota. From what I’ve seen it works, but I’m unconvinced that having me decide what to rate will give the best results.

So, can somebody comment about the sanity of the model proposed here, and (ideally!) tell me it’s implemented somewhere?