7 is the perfect number for me, I'm about half way there.

Modern road bike - yes
1950s road bike, golden age stuff - yes
City/sport bike for commuting - yes
Late 1930s road bike, first sanctioned derailleurs - almost there
1920s road bike, flip/flop only, a truely HTFU bike - not yet
1980s road bike, the height of old school technology - not yet
Optional track bike - not yet