I think Casino Royale has the best bond girl.

Vesper is great! She's a very complicated character. She is extremly loyal to her boyfriend even if she has to do dirty stuff for him. Yet she loves bond too and it's so deep that she would sacrifice her own life to save bond. Her love to bond despite her love to her boyfriend in one aspect emphasize bond's personal charm which is one thing I like about her. Her death in the end is very beautiful yet very sad. In the end she gave bond that desperate look and told him "i'm sorry", it's just heartbreakingly sad. She caught Bond's heart(not just sexually). She has dark secrets. She's like a combination of Tracy and Elektra(both are rarely seen deep bond girls). Eva Green did a great job on this character I think.