Both fighters have fantastic resumes. Two true legends of the sport, willing to take on tough opponents and gamble it all. I know this is a little odd as Bhop is still active, but tell me ESB, which resume do you think is better?
It's not a challenge. Hopkins has been around longer, stuck around long after his prime, and has a greater depth to his resume than Calzaghe. If Hopkins had retired in 2005/06 that wouldn't be the case, because his Middleweight resume is rather weak reflecting what was a weak division at the time, but he's gone on to prove his worth at Light Heavyweight. Probably the only victory Calzaghe has that is better than any on Hopkins' resume is the one over Hopkins himself, and that was a close fought fight and remains a controversial decision to this day.
