I can't speak for weekday rush-hour periods (Mon. 6-8am & Fri. 2-5pm), however I've never arrived at the airport more than 1:45 before a JetBlue flight. I've had some semi-long pre-security lines (20-45 minutes), but never longer than that. If it were me, I'd arrive around 1:30 before the flight...but if you're traveling with your family and/or are planning to eat before your flight, I'd think 2 hours would be plenty.