There is no official list of hand measurements for the NBA players, so technically no one player can be given that title at this time...
But, Shaquille O'Neal is 7'1 ft tall, weighs 325lbs and wears a SIZE 23 shoe...so based on these facts it is reasonable to hypothesize that he has one of the biggest sets of hands in the NBA.
Are they the biggest though?
Contributors say:
At the ESPN Sports Bar in Orlando near Universal Studios, they have statues of basketballs outside with the NBA players hand imprints in them. Tim Duncan's and Kevin Garnet's fingers are at least a half inch longer than Shaq's. I put my hand in all of them. Patrick Ewing has very large hands also. Long fingers should not be confused with large hands.
Rondo ?
Easily Shaq, he has one of the biggest hands in NBA history.
Manute Bol is the biggest player in NBA history.
Lebron james is the biggest disappointing player in the nba in the fourth quarter
Biggest is Shaq, tallest is Yao Ming
No nba is one of the biggest sports in the world
Dwanye Wade
Michael Jordan has some of the largest hands among non centers in the history of the NBA (Since the merger). His hands are arguably as large as many of these centers, including Shaquille O'neal, with measurements made at 10.5+ inches from the base of the palm to the tip of the middle finger. Rajon Rondo has the largest hands of any point guard in history at 9.5" from base to tip.
Kevin Garnet
Manute bol 8'6''
Kwame Brown
Though somewhat subjective, a drummer would have quicker hands than an NBA basketball player.