This superb hilltop German-run hostel outside Port Antonio has astounding views over the coast. The dorm is spacious and the doubles are well presented, plus there's a cottage looking out to sea. The kitchen is well set up (buffet breakfast is included) but the real gem is the veranda with views, and the peace of getting away from it all.
It's some distance from town, but the managers will pick you up and do a transfer run into Port Antonio a couple of times a day (a route taxi from Port Antonio to Stony Hill will take you most of the way).