Argentina versus England '98.
The joy in having won then was just undescribable. It was suuuch a tense match. (I was abroad when '86 happened.)
Also when Argentina won the gold in basketball.
It really, really sucks to lose in the world cup though. I was depressed for a week after the last WC.
Not as much as my older brother though, he locked himself in the car with a bottle of liquor and cried himself to sleep listening to opera.