We love JetBlue. We flew from JFK to Orlando with them for our last WDW trip, plus a few other routes they do. If JetBlue goes where we are going, we fly with them. We love how they've always left on time or earlier, plus the comfortable seats, friendly service, Direct TV, and cheap fares!
On a sligtly trivial note (but maybe not, you decide), I like their little extras. Like when DH and I took a flight from JFK to Buffalo about a year ago, they had baskets of freshly picked NY State apples at the gates (both at JFK and in Buffalo) for passengers to take. They were really good, and it's not too often an airline provides fresh fruit.