As a movie fan (and, yes, as an industry semi-professional), I've always loved The Internet Movie Database, AKA IMDB. Back in the olden, pre-Web days, a number of movie fans congregated around the USENET group rec.arts.movies (since split into many other areas). A guy named Chuck started collecting movie information and encouraged people to share their votes on movies. Eventually, this blossomed into IMDB, now owned by Amazon.
Much as I really love the IMDB voting feature, I've only ever voted for a small fraction of the movies/TV shows I've seen. So, here's my rating chart, for the movies I've remembered to vote for. The ratings skew high, but that's because if a movie looks bad, I don't bother seeing it.