Kind of replying to myself here, but just if anyone is interested, here was IGN's Top 10:
10. Grand Admiral Thrawn
9. Chewbacca
8. Boba Fett
7. Princess Leia
6. R2-D2
5. Yoda
4. Luke Skywalker
3. Obi-Wan Kenobi
2. Han Solo
1. Darth Vader
They also have some
video up with a number of celebrity choices (many taken from Comic Con). It seems like Han Solo, Boba Fett, and Darth Vader are the most popular answers.