Skyscanner – compares millions of flights to find you the cheapest deal, fast. When you find your flights and click to book, they link you directly to the airline or travel agent. No hidden charges, no added fees. They also compare and find the cheapest hotels and car rentals.
Cheapflights – they offer a wide variety of domestic and international travel options, showing deals that depart from airports across the United States, we can help you find cheap airfare that fits your travel plans and budget.
TravelZoo – a USA flight search engine.
Ebookers – big and multi-tasking but can be slow and not really a flight specialist.
Cheap Tickets – established for fifteen years
Expedia – convenient for multi-bookings but slow and a little old fashioned.
Lowest Fare – well established discount full service travel services provider.
Travelocity – largest online booking agency but somewhat cumbersome and rarely the cheapest, they do have a lot of administrators to support!
Worst Airport Terminals (2 serving New York City! ) | Useful air travel information sites (seat pitch, baggage delivery, flight tracking etc)