Dunno about best; there have been so many.
Most important: Morley at Bradford to make it 1-1 with 5 minutes to go. From Paul Cooper cutting it out at the back and running it through the spine of the team for White to put it on a plate for Morley, I think probably the most important goal in our recent history. If we loose that game, with the financial position of the club at the time, we very well could have been dead and buried now, or at least floundering in the lower leagues; certainly not top (joint top my arse) of arguably the greatest club league competition in the world.