Earlier this year John Romero made a DOOM level. That in itself was interesting, considering it was the first DOOM level he'd made in like 20 years.
In this video he does a pretty cool walkthrough of the level. If you have any interest in game design -- or you're curious about how DOOM works -- this is well worth watching.
So watch it ya big dummy!
One cool thing: John Romero wanted his level to be something of a homage to other DOOM levels. Interesting.