One game! No way dude. Because of DOSbox, I have created a single 4 gig hard drive image that I have burned onto a DVD. I would save that DVD before any single game.

Since you wanted to now which game I would replay the most. Right now think it would be Half-Life 1. That game is non stop shopping, with all the free mods on the net it provides endless joy.

If it were 1994 and my house was burning down, I would have saved Ultima VII.

Williams Arcade Classics: Must.....have.....Defender.....

DungeonMaster. Without question. Although as I've been collecting all I can for it to build a website (inlcuding rare Japanese versions), I'd have to save the whole lot -- it's worth a fortune.

Gothic1 & 2 (for me it IS one Game 😀 ) ps: the version from Piranha Bites (if there should be an other version too)