One of my oldest friends Mark, GM'ed Gamma world in a way I had never encountered before. The first time I played Gamma World with him (1987) he put a single sheet of graph paper on the table in front of me. It was basically a 2d geomorph of about 4 city blocks.
Imagine a top down view of this:
My character never left that map and still resides there to this day. In my time exploring that single sheet of graph paper I've met a biker gang that held out in a Gas station/garage, flesh eating "crazies" from the sewers at war with gator-men holding out in the water plant. Robot controlled electrical power substation, that I stayed away from. These guys who captured me, dosed me with radiation and threw me back out on the streets with nothing.
This is probably my fondest memory of Gamma World as a player. I was always excited when Mark would say he felt a Gamma World game coming on. I have more stories of Mark and his single page Gamma World maps to tell so watch out!