Misty May-Treanor and Kerri Walsh
Sport: Beach volleyball
Main rival: Tian Jia and Wang Jie, China
Breakdown: Have there ever been two people who represent their sport like this pair? Can anyone name a single beach volleyball player -- man or woman -- besides Misty and Kerri? Can anyone imagine them apart? (The two faced each other in high school, and Misty teamed with Holly McPeak in Sydney, finishing fifth.) And maybe the biggest question is: Can anyone imagine them losing? The duo has won 17 straight tournaments and 96 straight matches -- both records -- including gold in Athens, where they did not lose a set. Still, the Chinese have roared to within shouting distance of the American duo, and Misty and Kerri might actually sweat in Beijing for reasons other than the heat.