WebGames

Games and toys found on the web...

...that need shockwave/flash:

[Pacman]: classic pacman.
[Gridlock]: drag blocks around, in restricted directions, to get the colored block out of the exit.
[perpetual bubble-wrap]
[Freenet]: rotate blocks to connect up a network with one source and many sinks.
[Samorost]: The only justification that Flash needs. There's also [a sequel] now. [Quest for the Rest] was made by the same people, to promote a band.
[The Crimson Room] and its sequel [The Viridian Room] : escape from a hotel room. Neither are particularly good though.
[Grow]
[Mystery of Time and Space] - like the Crimson Room but tons better.
[Missile Command] - in Japanese
[Zyrx] - view a grid of coloured dots, memorise it, recreate it by clicking on another grid.
[Sticks]

...that need Java:

[Cube]: attempt to pick up blue squares on the sides of a rolling cube
[Nonograms]: Figure out which squares need to be filled in to give the correct sequences for the rows and columns.

...that need Javascript:

...that need no client-side intelligence:

[Go] and [SpaceHulk]
[Nation States] - run your own country
[Vampires! The Dark Alleyway] - Sorta-RPGish, pretty simple.
[The Alien Adoption Agency] - Another RPGish thing, a lot more complex as it's been going longer. Strangely addictive.
[Gothador - Devilishly Good Fun!] - More RPGish-ness, launched in April 2004, pretty complex for such a new game.
[Kingdom of Loathing] - Its currency is meat and you get to battle psychotic canned tomatoes. No more need be said.
[n.nfshost.com] - Not sure this game has a name. The goal is to progress to as high a number as possible. No, it is not broken in your browser.

...that require no intelligence at all: