US vs. Mexico matches are always interesting to watch because of the dynamics that exist between both teams, there's a history that precedes every match and you can see how hard each team wants the win (big!) more so than when they face other opponents. Not to mention that the games always appear to be sellouts whether in the US or in the Azteca. Last year's win at the WC (which was as major as you can get) gave us one of the greatest displays of the rivarly between the two. It's very much like the England-Argentina rivalry, it's entertaining for the fans and it's soccer at its best.
The score in the 91 Gold Cup game was 2-0 to the US, not 1-0. Goals from Doyle and Vermes, I do believe.