I'm pretty sure Doom will be the most popular (and my pick too), but I'll throw a shout-out to Epic Pinball; that Android table was the best one in the game anyway.
I didn't realize anybody else had ever played that game. I downloaded that from AOL back when I was signing up for a free month trial every month from those CDs in the mail.
There's a whole community around self-made games using the editor that came with it, including a website full of games and a forum. A few years back one of us published a book about the community (and how we all turned out trans).
I was so addicted to ZZT back then! The player-made worlds were such a delight, and my slow-ass computer which choked on so many then-current games ran them without trouble.
ZZT is officially freeware these days, too! The last original floppy was purchased about five years ago, and afterwards Sweeney declared the program officially free to use, though sadly not open-source. I believe it has been successfully decompiled for over a decade, though.