With hindsight...
1904: TR
1908: Debs
1912: TR
1916: Hughes, reluctantly
1920: Cox
1924: LaFollette
1928: Thomas
1932: FDR
1936: FDR
1940: FDR
1944: FDR
1948: Truman
1952: P: Kefauver G: I Like Ike
1956: P: Kefauver G: Eisenhower
1960: P: Humphrey, I suppose... too many candidates!
G: JFK
1964: P: Rockefeller G: LBJ, I guess...
1968: P: McCarthy G: Humphrey
1972: P: Muskie G: McGovern
1976: P: Bayh G: Carter
1980: P: Carter, halfheartedly G: Carter
1984: P: Hart, just for kicks G: Mondale
1988: P: Simon G: Bentsen
1992: P: Kerrey? G: Perot, for being silly
1996: P: Lugar, for being a Hoosier G: Perot, for being my first political (of any sort) memory
2000: P: Gore G: Nader
2004: P: Dean, then Edwards G: Kerry or Cobb