4. Black Canary - Yvonne Strahovski
You might not know who Yvonne Strahovski is but fans of Dexter will sure know all about her. The Australian beauty not only looks perfect for the role, she is also a trained martial artist. Blonde, beautiful and worthy of an action-packed role, Strahovski has already proven she's got the acting chops and physicality to play Black Canary with her role as Sarah Walker in Dexter almost acting as one giant audition for the part. At 27, she's the perfect age for the other cast members too. Black Canary's involvement could open up the door to an appearance from Green Arrow too. The New 52 has changed certain parts of her back story but she's still an important member of the team. Also, one of the most exciting prospects of including Black Canary would be a potential Birds of Prey movie. This would be a good way to build back story for future characters important to the JLA such as Oracle and Huntress, without the need for origin stories.
Notable Mentions: Jessica Biel, Jaime Pressly, Kate Beckinsale