My personal favorite is probably Vesper Lynd from the new Casino Royale or Wei Lei from Tomorrow Never Dies--I like a Bond girl who's actually revelant to the story and a real character.

As far as hottest, without question the one played by Lana Wood (Natalie's sister) in Diamonds Are Forever, followed by Carole Bouquet (For Your Eyes Only), Eva Green (Casino Royale), and Lynn-Holly Johnson (both in For Your Eyes Only).