Model Citizen

Remember DOOM? Of course you do.
I downloaded JDoom yesterday from this site:
Doomsday
It allows you to play the old Doom games with high res graphics. Absolutely brilliant! It's completely free too! All you need is the original WAD file that is on your old DOOM disk. You can use DOOM, DOOM 2 or Ultimate DOOM, or even all 3.

Plus if you have a gamepad, you can use YoyToKey to emulate the keyboard commands.
JoyToKey is worthy of a mention all of it's own. A brilliant little application that emulates keyboard commands into joystick/gamepad commands. It's easy to use and so far I've succesfully used it on all the old Tomb Raider games.
It can be downloaded Here

Good gameing