The most impresive ever was Diego Maradona playing for Napoli (1984-1991). Took a less than average team to win everything:
Serie A: 1987, 1990
Coppa Italia: 1987
Capocannoniere: 1988
UEFA Cup: 1989
Italian Super Cup: 1990
Currently:
David Beckham with LA Galaxy
Robinho with Manchester City