I have been meaning for years to link to TV Tropes, a wiki that provides a vast and entertaining and heavily-interlinked “catalog of the tricks of the trade for writing fiction.”
I would have suspected that I've delayed linking for so long that most people know about it by now; but there's only one of my regular online hangouts where people ever mention it. So perhaps some of y'all haven't encountered it.
For those who haven't: each page covers a single trope that's common in fiction. (Not just TV: also books, movies, comics, roleplaying games, computer games, professional wrestling, and other narrative forms.)
Also, each trope's page includes lists of examples, usually dozens of them, from all kinds of media.
And it's all a wiki, so you can add to the site if you're so inclined.
The site is not, as it may initially appear to be, a catalog of cliches or overused plot devices; tropes are tools, neither bad nor good in and of themselves. That said, a lot of the catalogued tropes are heavily overused, and authors who use them may want to think about ways to use them freshly or interestingly.
Having linked to the site, I have to give this warning to those who haven't visited:
Don't follow that link.
Following a link to a TV Tropes page generally results in hours of reading entries, reading examples, and following links to other pages. I know some people get lost in Wikipedia that way, but for me a Wikipedia foray rarely involves going more than three or four links deep. Whereas on TV Tropes, it's hard for me to stop after only three or four links.
The addictiveness of TV Tropes is partly because there are so many links between entries, and partly because the entries themselves are interesting, but mostly (for me) because so many of the trope names are so tantalizing.
Sometimes the titles are less obvious names for things I knew about. Lampshade Hanging, for example, is the act of calling attention to an implausibility or blatant use of a trope. The term apparently comes from the Mutant Enemy people (Joss Whedon et al).
And sometimes the titles are very specific, often about things that I hadn't really noticed as tropes, such as the Bizarre And Improbable Golf Game.
A lot of why there are so many links among tropes is that there are a lot of very specific tropes and variants, so the wiki has to differentiate among them. Also, some tropes are opposites to others, and some are related in other interesting ways.
I do find some of the very common names a little non-intuitive, especially when they come from sources I'm unfamiliar with. For example, there are a whole set of tropes built around the Xanatos Gambit, in which a planner manipulates things such that no matter how things come out, the planner wins. The name derives from a character on the TV series Gargoyles, which I've heard good things about but have never seen. And then there's the Logic Bomb, used to confuse AIs since time immemorial.
But mostly the names just sound interesting. It looks like some of the more obscure ones have been renamed to more obvious names lately, but there are still plenty of unusual and interesting ones. Who can resist clicking a link to a trope called Applied Phlebotinum or Exposition Party or Epileptic Trees or Everyone Is Jesus in Purgatory or Dead Unicorn Trope or Too Spicy for Yog Sothoth?
Yes, yes, I know some of you have now resisted clicking all of those links. Well done! You have a chance of getting something useful done today.
I should note that the other reason writers should be wary of following links to TV Tropes is that it's easy to read through the tropes and think Oh, no! My story uses this trope, and this one, and this one—I'm writing nothing but cliches!
So in case you do go and start reading TV Tropes, I'll close by repeating my note from earlier: tropes are not inherently bad (nor inherently good). Knowing about them can improve your use of them.
But still, be wary and careful in their use, especially in using the ones that are already widely overused.
And remember: don't follow links to TV Tropes.