A friend of mine had a copy of the Games Workshop Judge Dredd RPG but we never got around to playing it. But I remember thumbing through the pages and imagining what a great time could be had playing in the cut-throat world of Megacity One.
Mongoose has had the rights to publish JD for quite some time now and they are currently offering the miniatures game as a free download on RPG Now!
Mongoose also offers their own line of miniatures for the game as well as Wargames Foundry's 2000 AD and Street Violence lines. And if you prefer 15mm there's 15mm UK's Laserburn series. Now to decide on a scale, Drok it!