Stanford in the 1998 Elite Eight.
After coming back to beat Duke, it seemed like people just assumed the Cats would at least make the Finals. But Stanford was a terrific team playing at a high level. That whole game was played at an insane level of intensity. I remember Dean "The Educator" Smith had just retired and was acting as an analyst for CBS and he blurted out after the game words to the effect that, "that was the best basketball game I've ever seen."
Incredibly clutch play to erase a double-digit halftime deficit. And a legendary performance by Jeff Sheppard hitting three 3s off curls late in regulation and in overtime -- watch it again, if he misses any of those shots I think Kentucky loses.