I highly recommend Lindsay McFarlane. We used him for airport transfer and also 2 excursions during a recent stay in Montego Bay.
We went to Dunn's River Falls, and while we were there we also went up the Skyride (like a ski-lift chair with amazing views of the ocean) and did the Jamaican Bobsled (so much fun!) and you can also do zip-lining there. We also did a day of touring and shopping, Lindsay suggested where to go and he showed us all kinds of amazing places in and around Montego Bay.
Next time we are thinking of going to Negril. If you want ideas, I'm sure you could email Lindsay and tell him what kinds of things you like to do and he would design an itinerary for you.
I truly can't say enough about him or the service he provided. It is well worth every penny - you will not be sorry! His English is excellent, his van is safe and well air-conditioned, he brings a cooler so you can pack drinks and snacks, and he is extremely cautious about always locking the vehicle so your stuff is safe and he is always concerned for your safety and well-being.
Additionally, he is incredibly knowledgeable about the island, history, flora and fauna, and will make your transfer and/or tour very interesting (and take you places you'd never otherwise get to see on an excursion.)
If you book him for a tour, he is very conscious of making your day worthwhile so you feel like it is money well-spent. By the end of our trip, he felt more like a friend than a tour-guide/driver.
Lindsay McFarlane (SNL Jamaican Tours)