Last night the five of us decided to throw an impromptu Fonseca Vertical. Covered were all vintages from 1970-1983. The line-up consisted of: 1970, 1975, 1977, 1980, and 1983. '75 and '80 are both difficult vintages to find. 1977 got 100 points in Wine Spectator, and 1970 got like 97 or something.
To me, 1970 and 1966 are the two best drinking post war vintages... Well, I should include 1955 and 1948, but those are quite costly at this point.