I've bought a bunch of different types over the years.
Most comfortable small one is the folding chair I picked up at a Pick and Save on a whim, folds small and lightweight. Travels nicely on the overhead bed.
Most comfortable overall is the "gravity chair" sold by a few different manufacturer/retailers but they don't fold to a point where they are really truck camper friendly.
Bag chairs are the easiest to store but I've not found one that I really like, of course I refuse to spend the big bucks and all the ones I've got were < $20. I do keep a couple of the better ones up beside the bed for when friends show up around the campfire.