bush
By all the conventional methods, plus he is one of a select group of people to have traveled frequently on Air Force One, the Presidential plane.
Obama
There is no public record of the exact mileage President Obama logged on Air Force One during his presidency. However, it is estimated that he traveled over 2 million miles on the aircraft.
The President does not fly Air Force One- he flies ON Air Force One
That is an interesting question, since nearly every modern president has gone overseas to attend diplomatic meetings, lead a trade mission, or commemorate a particular event with other international leaders; years ago, these trips were conducted by ship, but in the modern era, Air Force One is the mode of transportation for the president. Some sources say both President Bush and President Clinton made the largest number of trips-- in two terms, they visited 74 different countries. In his first term, President Obama visited 35 countries. I enclose a useful link about presidential travel in the modern age.
the president uses air force one because that air port is safe and secured for the president
Air Force One will remain Air Force One no matter who the President is.
Air Force One is the Air Traffic Control call sign for any aircraft carrying the president. Air Force Two can be an identical aircraft, carrying the Vice President.
on air force 1
Air Force One.
While in office whenever Nixon traveled within the United States he rode in a military helicopter. If he was going overseas he flew in Air Force One.
The current president and his family use air force one