There's nothing like football to give you a heart attack! Good question about club vs. country rivalry. Its hard to say - most people I know in England care very, very passionately about their local clubs. This said, when Euros or World Cups come around, everyone's focus is honed to the national team and the atmosphere is tremendous!
I don't suppose many know too much about the brillian sport of cricket, but if we're talking about nail-biting, heart-in-mouth, nerve-jangling stuff, then this has to be it for me.
As for your question about emotional anecdotes, watching pakistan win the (field) hockey world cup on penalties when I was about 7 ... just can't forget it.
Sport in my opinion, is the best thing in the world. Nothing gets me more emotionally charged.