Where to find on-line ESSAYS about film?

I can search IMDB and find reviews, which are essentailly recommendations to people who are considering seeing movies. These are replete with careful spoilers, not revealing much about the plot, the ending, etc, but how do I locate serious–or at least competent–essays online that discuss the films with the assumption that the readers have already seen them?

Googling turns up a ton of garbage, and the “Cafe Society” links are usually better than the reviews, but I suspect that there are discussions on-line (somewhere) that are more detailed and more professional.

I’m off to search the SDMB but will appreciate the help if anyone’s got some.