frostbit_sky gave me:
Keira Knightley: I could say The Phantom Menace, but she only has something like 3 or 4 lines in it, and she's not exactly the star in it either. I liked her in the BBC mini-series of Dr. Zhivago, but I'm going to have to go with Pirates of the Caribbean: Curse of the Black Pearl, the movie that made her a star!
Angelina Jolie: Hackers was her break-out role for me, and I highly recommend renting it just for the out and out silliness, but Mr. & Mrs. Smith is my favorite of Angie's so far.
Cameron Diaz: Did you know she was in The Mask with Jim Carrey? Amazing what a haircut can do for a person. (I also just discovered that she had a cameo in Minority Report! Hmmm, I'm going to have to check that out.) Anyway, I'm going to have to go with A Life Less Ordinary which is kinda a cult favorite of mine.
Natalie Portman: Despite how obsessive I may seem to be about her, I've only seen her in (one, two...) four non-Star Wars movies! My favorite non-Star Wars movie is a toss-up between The Professional and Where the Heart Is, but my favorite overall is The Phantom Menace Did you know that she's going to be in Thor next year? Despite the reluctance voiced by some people I'm actually looking forward to seeing her in Pride and Prejudice and Zombies.
Nicole Kidman: It's very tempting to pick Days of Thunder ("Stop the car, Cole!") or Malice ("Ask God how many shots of bourbon he had before he cut me open."), but, come what may, I'm going to go with Moulin Rouge!.
Harrison Ford: Hollywood Homicide. No, just kidding. :) Star Wars is very tempting, but that wasn't exactly his movie, but Raiders of the Lost Ark was, and that's what I'm going with.
Johnny Depp: Did you know that he was in the original Nightmare on Elm Street? It's amazing what you can learn at imdb.com, isn't it?? Anyway, while I got a good chuckle out of his character in Once Upon a Time in Mexico, nothing beats Captain Jack Sparrow in the POTC movies, so that's why I'm going with Pirates of the Caribbean: Curse of the Black Pearl.
Christian Bale: The guy has two middle names, but surprisingly neither of them are Intense. I'm tempted to pick Empire of the Sun, but Batman Begins is my favorite of his. I think The Dark Knight is a better movie, and while Christian was the lead-character, that movie belonged to Heath Ledger.
Ewan McGregor: Oh, this is going to be tough. I've already mentioned three films he's been in, and I've seen quite a lot of his movies since 1997. TPM could be my default choice, but he was good in Revenge of the Sith, too, but I'm going to stick to the film that introduced me to him: A Life Less Ordinary. I've watched that movie far too many times for it to not be my favorite of his.
Orlando Bloom: I'm very tempted to say Black Hawk Down where the pretty-boy falls out of a helicopter. The Lord of the Rings: The Two Towers will be my choice because his fun reparté with Gimli (John Rhys-Davies) was one of the highlights for me in this part of the trilogy.