One reason I like doubles is that I can have two different chokes if I want them. But if I had to be limited to just one choke I could be happy with I/C or even Lt. Mod, but IM or full have less usefulness than more open chokes for my shooting needs. I think one proble with fixed chokes barrels are that too many of them are too tight for most people these days. That and pump guns are a tough sell these days because people who have never shot them think they are slow but I find I can pump faster than I can get back into target for a second or third shot. Not slow at all.
So if you had only one choke what would it be?