I wont say what year is the best or my year is the best but u gotta look at what u want out of ur truck n what u wanna do with it, so ill share what I know n understand
05-08 Pros - real LSD, alot of performance options, rear seats can fold flat(if u need to store something back there
09-11 Pros - '11 came with back up camera, new colors 09 was BRM, 11 was black, new gauges, new rear seat design, subwoofer, rear sests had headrest added, side airbag, led taillights, dark chrome headlights
12+ Pros - new color NBM, turn signals in side mirrors, new front end, more black interior,