Everyone has their favorite. I have used a few on the list and frankly they all have been awesome. My vote goes to Kingsley James and if you plan on doing a tour I would encourage you to check out his website as he offers up a value with a free airport return on select tours. In fact, I have been in his vehicles over 30 times and he was only late once. It was due to a motorcycle fatality on the wicked corner by Llantrisant, and he was still there shortly after the stated time. He has taken us all over Jamaica, from the West Coast, to the South Coast, to the North Coast, to Bob's birthplace and all rides are comfortable and without worry. The drivers recommended on this site have all been vetted and you would be hard pressed to find a ride that sucked.
Shout out to Dudley Warren as well as his son Matthew, who is in the process of getting his red plate and will surely be an approved driver on here in no time.