On domestic flights, Business class has a little more legroom than coach, and depending on the airline, better snacks, free headphones, or early boarding. In First class, you have the most legroom, a dedicated flight attendant, a good meal (well, for airline food!), and booze is free. On International flights, business class offers almost the same amenities as first class (again, depending on the airline).
at 7:38 AM on Aug. 30, 2010