I'd go for the Foster promotion season early 90's, I think we went top with a win over Torquay over Christmas, and I think I remember our defensive record was the best in the league.
Edit: Sorry I've just looked up the season I was referring to and it was neither Foster, nor Christmas, and not the right answer either. So ignore me.
Controlled & Clueless. If this is the big life, well I ain't looking to live it.