Mac user though I am, I dig playing old DOS games. I’ve been using DosBox, which is a great program. Even better however was my discovery of Boxer, a DOS game emulator designed specifically for the Mac. It’s even easier to install, play and manage classic DOS games.
Another great application is img2icns [image to icons] which allows you to give any file a new icon. Handy for those great DOS games which are playable as a double click icon thanks to Boxer above.