Re: Let's talk love interests/leading ladies.
Not counting Catwoman, who isn't really a traditional love interest in her many iterations, my favorite is Gwyneth Paltrow's Pepper Potts. Her spats with Robert Downey Jr are a highlight of the Iron Man films. They have fantastic chemistry. She's the second best character in those movies, which is really quite an achievement.
Worst is the Katie Holmes version of Rachel Dawes who is the clear weakpoint in an otherwise great film.