In general I would say JD for me. They are both mode based games, but JD offers more depth and a more original playfield (JP's is a very clear Lawlor ripoff, very similar to TAF and WW). Dredd's only tragic flaw is the increasing value of the left ramp. If you get good at that shot, the best strategy for points becomes shooting that over and over again, making the scoring unbalanced. If that's not something you could see yourself doing in a home environment, then go for JD.