IMHO JetBlue are outstanding. Cheap fares and real nice attitude thereafter - none of this extra charging for any changes. I recently flew LHR-JFK on VS, arrived early and found I had 4 hr to kill in T6 at JFK before my connection to PBI. They let me go standby at no extra charge on the earlier flt, so I was a/b JFK in under 1 hr from landing on VS!
New A320, free TV on board (24 channels), free headsets, free drinks and cookies/crisps. On return I again managed standby for an earlier return at no charge. Same excellent service and then to cap it all on pushback ex PBI all the gate staff came down to the extreme edge of the active taxi-way and as we rolled forward to go, they all waved like we were their personal best friends. I couldn't believe it, but felt a million bucks. You have to hand it to them - great airline, great service.
Two other things: in T6 at JFK they give you free Wi-Fi access (most US apts charge you $8 a day); and also their fares can go down nearer to the flt date, unlike FR/EZY. 3 days out the fare was $179, 2 days out it was $120, even though the flight was then showing 95% full.
I've flown almost 1000 flights and these guys were really best value for money ever.
(and NO, I don't work for them)