This article got me watching Tetris on youtube. I plan to check out the documentary it mentions; seems like a good complement to The King of Kong et al.
Flash games are a very important part of game dev history. But despite millions of games available on thousands of websites, I only ever played or will ever play tower defense games.
The Internet Archive's collection of DOS games you can play in the browser.
A site with a bunch of abstract strategy games (implemented in mod_perl!)
The rules of Tablut.
Nick Bentley's guide to abstract strategy games.
Everything you wanted to know about enumerating states of the game 2048 in one series of posts by John Lees-Miller.
David Kushner's Masters of Doom is on my reading list, though I'm more interested in the making of Commander Keen than of Wolfenstein and Doom (which I never found very fun).