Who would you rather have on your team? I'd personally pick Gerald for the defense, but JR Smith has a lot of potential, and Stephen Jackson can probably give you the biggest punch on offense.
Gerald Wallace for sure he is easily the best defensive player out of the 3 but he is also getting much better at scoring too. J.R. Smith is a good shooter and slasher but he really plays no defense at all and Jackson is really inconsistent with his game and also doesn't play much defesne.
