I'd say the Arsenal 99 semi was greater because of Big Pete's last second penalty save and Giggsy's insane solo and subsequemt celebration. This one is very high up on the list though.
Innit.
Not everyone can feel the Liverpool rivalry. Most United fans are giddy because it means so much as side from yesterday's game being pure box office and all. Perhaps the most exciting game I've seen for 20 years plus.