I'm 27 so unfortunately most of my highs that I recall have been in the last 5-6 years... without further ado:
For me, beating the Scum 5-1.. the atmosphere at the ground that day was the best I've ever experienced, ALL FOUR sides of the ground in unanimous voice for the whole match... and afterwards I was on such a high for at least a week, maybe longer. Because we fudging battered, annihilated, walloped 'em!! Sadly hadn't experienced that feeling before. That's my ultimate personal #1 and it will take a lot to ever beat it...
Although 2-1 at the Lane vs the Scum comes close... the way we finally ended that cursed league run!! Epic.
I agree with those saying CC Final against Cheatski - that was a big turning point in our recent history IMO, we stood up and took on a 'top' (*spits*) team with a lot of 'big' name players, and outplayed them, like Spurs are meant to do.
And Man Sh!tty "4th Place Final" away is right up there in my top 5. While I didn't enjoy that game personally, I was literally CHOKED with sheer tension/nerves... but the ecstatic feeling at the end was something else. We played with balls that day, and Ledley stood up and delivered a collossus, imperious performance even by his standards. I miss the big guy!!
Rounding off the top 5... I think I might put beating Man U at Old Trafford in at no. 5. Let's hope that too is another big turning point in our history. It's either that or owning Inter Milan at WHL, or AC at the San Siro...