The following actresses all were offered and declined the lead role in Gravity before Bullock accepted:
Angelina Jolie (twice), Natalie Portman, Jennifer Lopez, Rachel Weisz, Marion Cotillard, Carey Mulligan, Blake Lively, Scarlett Johansson, and Olivia Wilde.
Oops. They are all probably kicking themselves now.
how many emo kids does it take to change a lightbulb?
none they just sit in the dark and cry