Lists of plots and plot twists

Here are some sites that offer lists of plots.

The Big List of RPG Plots
Nice summaries of a large list of plots, each with a list of Common Twists and Themes.

Hatch's Plot Bank
Not really plots but mostly scenarios to spark your imaginations. Over 2000.

Strolen's Citadel List of RPG Plots
Submitted by members. All nicely organized by type. If you click on Plots in the page's horizontal menu, you'll have choices of coincidence, crisis, discovery, duty, event, hired, mystical, nature, travel.

Here are a select few:

Locations: This is a a city where your wealth, social standing and everything is decided by the society of prohecy who keep the rich, rich and poor, poor.

Character: A voice as supple as silk, a face hidden in the shadows of a hood, yet the words she speaks are colder than the grave and burn more furiously than any inferno.

Plots: At the base of the Cyllerean Mountains a small coven of witches has laired where once was a Temple of Good.

Systems: The Way of the Many - One spellcaster cannot achieve very much, but many minds can. Like insects, spellcasters are at their most formidable when they are united.

Item: The Tome of Life - Book with initially blank pages which records the life of the holder from the time it is picked up to the day someone else picks it up, at which point it starts again as blank pages.

Story Generator at TVTropes
Generate Setting, Plot, Narrative device, Hero, Villain, Character as device, Characterization device. A massive site you can lose several hours of your life to. It's a user generated compilation of tropes, eg, recurring character types, plot devices and so forth. It can be confusing at first, but check out your favorite movie and start reading through the tropes in contains and you'll get it.

Errant Dreams
The plot twists and hooks are primarily for role playing games but writing is mentioned often. There is a list of plots on the front page (a third of the way down) and, of particular note, The Instant Plot Hook, Plot Twists for Game Masters, Creepy Plot Hooks. These could be especially useful if you're stuck.

Basic Plots in Literature
Supposedly there is only 1 plot in the world. Or 3, 7, 20 or 36. They're all listed here.

Get a Plot
Some good summaries of some well known books written in general terms (for Role Playing Games).

imdb.com Search a Plot
Type in keywords and click Go. (Or, over on the left, click Alphabeticallly, by year, by country)

TV.com
Type in the title of an episode (it may display a list and you'll need to pick which one), click the Episodes tab and it will display synopses of the episodes for each season.

Archetype's Plot Scenario Generator
Provides the mess your character's in plus another character to mess it up further.