Meryl Streep introduced the honorees Saturday during a formal dinner at the U.S. State Department and noted that Letterman had surpassed his mentor, Johnny Carson, in sustaining the longest late-night television career for more than 30 years.
Stephen Colbert and Jimmy Kimmel joined in celebrating Letterman's influence on many other comedians.
To salute Led Zeppelin, big names from the rock world dressed in black tie for their music heroes as a string ensemble played the band's hit song "Kashmir" and other tunes at the State Department.
Lenny Kravitz said their influential music, at its zenith in the 1970s, became a lasting part of the culture of rock and roll.
Zeppelin front man Robert Plant said he was flattered and overwhelmed at receiving the American culture prize. He said he was glad to see his former bandmates John Paul Jones and Jimmy Page using good table manners.
Hoffman was honored for charting his own path after taking a junior college class in acting that "nobody ever flunks." Streep, a 2011 honoree, said Hoffman's quest to become an actor required waiting tables and typing for the Yellow Pages by day.
"He'd do anything if it meant at night he could find himself on the stage," she said.
Glenn Close toasted Hoffman for defining the character actor as leading man in such movies as The Graduate, Rain Man, and Tootsie - and as an artist who insisted on setting the highest standards for himself.
Former President Bill Clinton saluted Guy, the Chicago bluesman who was born into a family of sharecroppers with no electricity or running water in Louisiana. He went on to pioneer the use of distortion and feedback with his electric guitar.
"Buddy Guy's life is a miracle," Clinton said. "Just imagine you want to be a guitar player and you get your first strings by tearing off the screen door. . . . He came from that to this."
Secretary of State Hillary Rodham Clinton said Makarova "risked everything to have the freedom to dance the way she wanted to dance" when she defected from the Soviet Union in 1970.
Makarova quickly made her debut with the American Ballet Theatre and later was the first exiled artist to return to the Soviet Union before its fall to dance with the Kirov Ballet.