Well would you look at that. Archive.org has been working hard to preserve as much art and expression as possible, including some things that you would think are blocked by copyright holders. In this latest initiative, they have included DOS-era games in a JavaScript-based editor. Yeah, most of what I tried are pretty much unplayable, but it's a gigantic catalog none-the-less (over 2000 titles).
It has some titles like: Aladdin, Duke Nukem 3D, Bust-A-Move, Battle Chess, and Oregon Trail. Some of them, like Bust-A-Move and Aladdin, are not playable for me on either Chrome or Firefox due to low frame rate.
If you have a good PC, feel free to give them a try.
I tried this just a few hours
I tried this just a few hours ago, every single game I tried crashed, Jazz Jackrabit, Lazer Chess, Champions of Kryn, none worked more than a min, BUT it was super happy to see the old dos screen. Ahhhhh, the good old days, when using a computer ment some knowing some secret code that made you look like a nerd but you knew better, ahhhhhhhhh
I just tried a few like, Sim
I just tried a few like, Sim City, Donkey Kong, and Super Street Figher 2. They worked fine in the firefox browser.