From IGN - "Internet Archive has added nearly 2,400 MS-DOS games to its steadily growing collection of classic software, including Bust-A-Move, Commander Keen, and Metal Gear.
The library of historic and obscure digital games is made possible with the use of software curator Jason Scott's EM-DOSBOX in-browser emulator."http://uk.ign.com/articles/2015/01/06/nearly-2400-classic-ms-dos-games-playable-for-free-in-browser
Some classics available (not all play properly but that's not the point of the site anyway):
Pools of Radiance
Microprose Pro Soccer
Indiana Jones and the Temple of Doom