Here's the initial list of contenders:
1. Well Armed blows away the field in the Dubai World Cup
2. I Want Revenge overcomes a horrific start to capture the Wood Memorial
3. Rachel Alexandra runs off with the Kentucky Oaks by more than 20 lengths
4. Mine That Bird posts stunning, 50-1 upset in the Kentucky Derby
5. Rachel Alexandra turns back the late charge of Mine That Bird in the Preakness
6. Rachel Alexandra toys with the boys in the Haskell Invitational
7. Gio Ponti captures his fourth consecutive Grade I score in the Arlington Million
8. Rachel Alexandra holds off her male elders in the Woodward Stakes
9. Linda Rice becomes the first woman to win the Saratoga training title
10. Summer Bird registers historic triumph in the Jockey Club Gold Cup
11. Goldikova wins her second straight Breeders' Cup Mile
12. Conduit runs down the stubborn Presious Passion for a repeat score in the Breeders' Cup Turf
13. Zenyatta remains undefeated and becomes first female to win the Breeders' Cup Classic
14. Racing mourns the passing of Hall of Fame trainer Bobby Frankel