The published adventure from the old GW days my players enjoyed the most was Slaughter Margin. It may have been because of the floorplans that came with it, which made it nice and visual. I have converted several films and books for use in my games, my personal favourite genre for doing tis in Dredd is strightforward modern-day horror, which converts really easily. You just need to make sure the players haven't read or seen the source material
My team of Judges is made up of friends I know well, and I know what they watch and read is different from what I watch and read - Twin Peaks made a great epic campaign once I'd ditched a _lot_ of the subplots, (I even had demon Bob possess one of the characters at the end - with his full cooperation - so he could be a fearful adversary for the rest of the team, many of who had become too powerful over the course of a few yeas regular playing - he killed one Judge whos stats were almost maxed out and who was becomming a real annoyance) and the movie Se7en I used almost scene-for-scene - this needed one of the players to agree to have a secret lover for the sake of the plot and when he went crazy at the end it made for a very memoable gaming session)
My next big project (after we have finished The Awakening - about 2 progs to go) I think is going to be based on Carnivale, but I may well run the current 2000ad storyline (Total War setting off nukes in the City) in the background as it is so important (did this during the Necropolis era, too)
toni