It's basically a wiki that's all about the recurring tropes and cliches that show up in every kind of media. If you are interested in any one of tv, movies, anime, comics/web comics, video games or books you'll probably find the site amusing. If you're interested in more than one you're probably doomed :) There's generally pages for various media which describes whatever it is and then has a list of tropes found in that media, and a page for each trope which describes the trope with links to related tropes and then has a list of examples from various media.
Just search for a favorite media (tv series work very well) and go to the page and start following links. If you're anything like me you'll become trapped in an infinite loop where every page you visit results in more than one new tab being opened :)
Along with my general interest in the subject matter the site has pretty much all the stuff i like about wikipedia and so far at least doesn't seem to have any of the negatives. (Establishment biases against non-notability, fictional stuff and trivia and an obsession with citations.)
Some fun pages to look at if you don't want to start with a particular show: The Grand List of Console RPG Cliches, the Evil Overlord List the SciFi Writers Have No Sense of Scale page, and the Lampshade Hangings page (shows referencing their own tropes.)