In no particular order:
Juninho v Arsenal. Jan 2004. League cup semi final, first leg against the Invincibles. That was when I started feeling that this was our year.
Maccarone v Basel. April 2006. UEFA Cup Quarters. 90th minute winner to take us through to Steau, where he did it again!
Stuani v Brighton. May 2016. Championship. Stadium is bouncing, packed to the rafters, we only need a draw to gain promotion to the Premier League under Karanka. The party started at that moment and even a Brighton leveller couldn't dampen the mood!