My money is on destiny soley because of how many things he'd have to deal with and he doesn't have the mentality to try to wipe out a universe. He always wants a fair fight til someone admits defeat where as everyone else is aiming to kill. Not to mention how technical some of the bosses are and what has to be done to beat them. Id bet more on lord bills, whis and even majin buu (kid) over goku. If it was gokus power mixed with bardock and vegetas mindset I'd say goku but that's the only reason.