The rollercoaster career of Hollywood star John Travolta decisively discredited the old adage that there are no second acts. The New Jersey native first gained fame as a suave, dim-witted Brooklyn high school student on the sitcom "Welcome Back, Kotter" (ABC, 1975-79). Being in the right place in the right era, he became inextricably linked to pop culture trends, thanks to sensational starring roles in the disco drama "Saturday Night Fever" (1977) and the 1950s retro musical, "Grease" (1978). Travolta also had a hand in the country music revival of the early 1980s with his popular portrayal of a mechanical bull-riding oil rigger in "Urban Cowboy" (1980). Then for some reason, the biggest male movie star of the late-1970s languished throughout the next decade and beyond, his engaging talent virtually forgotten until a bold decision by Quentin Tarantino cast him in the cult mainstay "Pulp Fiction" (2004). Following the rousing response to Travolta's darkly funny performance as a junkie hit man, he was overnight commanding millions of dollars for macho hits like "Get Shorty" (1995) and "Ladder 49" (2004) and becoming one-half of a celebrated Hollywood couple after marrying Kelly Preston. Critics raved when Travolta made a belated return to his musical roots in as a tubby Baltimore stage mom in the box-office smash "Hairspray" (2007). In fact, Travolta defined more than any other celebrity - save perhaps Cher and Frank Sinatra - the very idea that a so-called "has-been" could revive a career deemed long dead, coming back stronger than ever.