The first one I really remember was Apollo 11, since we were having a family vacation in Florida at the time, staying at my cousin's hotel in Winterhaven. We watched the lift-off on TV, then went outside and soon saw the flame of the Saturn V rising in the distance.
With binoculars - and perhaps a little bit of imagination - I convinced myself I could make out a tiny black dot at the apex of the plume - the rocket itself.
That was history - and IMHO, one of mankind's greatest achievements.