NBA Most Valuable Player Award was created in 1956.
NBA Most Improved Player Award was created in 1986.
NBA Development League Most Valuable Player Award was created in 2002.
NBA Development League Most Improved Player Award was created in 2010.
NBA All-Star Game Most Valuable Player Award was created in 1953.
Bill Russell NBA Finals Most Valuable Player Award was created in 1969.
Kevin Durant of the Oklahoma City Thunder won the 2013-2014 NBA Most Valuable Player Award.
NBA Rookie of the Year Award was created in 1953.
Considering that their are only 4 given out for the entire season (Rookie Challenge MVP, All-Star Game MVP, NBA MVP [for the season], and the NBA Finals MVP), the most prestigious would easily be the NBA MVP award.
NBA Finals most Valuable player
The answer would be Micheal Jordan.
Michael Jordan won his second NBA MVP award in 1991. That was for the 1990-91 season.