I picked the 2001 US Open quarter-final match. As more a Sampras than Agassi fan, I knew, just KNEW, that, with his bad run of form and three consecutive losses to Andre, if Pete lost the first set he was doomed. And he lost the first set. And went break points down in his first service game of the second. And somehow dug himself out of a hole to win. Not the best ever performance from either of them but I think the best they both played while playing each other.
The 2000 Aussie Open semi was great... for four sets. Andre ultimately won on fitness and was the deserved winner that day. I'd pick that as the best big-stage performance from Andre against Pete and even then Pete almost snatched it in four. The fourth set tie-break was terrific.
Third, the 1999 Wimbledon final has to go down as one of the most amazing, devastating displays of attacking tennis ever. Shame it wasn't a great match.
Matt