So many good memories from reading this thread.
The most important have to be the ones from 76/77 already mentioned (1-0 v Pompey to clinch promotion, 0-1 at Arsenal opening game, 2-1 v Liverpool & 2-2 at Coventry to survive).
One not mentioned worth a mention was beating the Gas at Eastville in the old div2 in 1974, blowing a gale with the wind behind them Gas 1-0 up at HT, but with the wind at our backs we come back to win 1-4. Many of the eventual promotion side playing.