Favorite film with William Holden? That's easy. The first film I knew him from, The Horse Soldiers (1959).
This is one of those movies I don't really have any memory of seeing for the first time, because it was part of the John Wayne round-up of films we watched whenever they came on TV. When I was little, I loved Constance Tower, in her gorgeous dress, cleverly scheming to find out the Yankee plan. I loved her spitfire attitude, her attempts to escape or warn the Confederate soldiers, how she changes as she witnesses war and its cost. But I never did understand why she fell for John Wayne and not that other guy, the doctor, the one who was so good-looking and willing to go toe-to-toe with John Wayne. That William Holden guy.
I loved his character of Major Kendall. He starts out friendly, here to do his job, but Colonel Marlowe (John Wayne) just lays into him from the get-go. Kendall's not one to let it wash over him, so the animosity between the two men grows. This is one of those movies that even though I own it on DVD, I can't just scene jump to the "good parts" at the end. There's quite a few movies like that, where jumping ahead just ruins the ending, because what makes the ending work so well is sitting through the rest of the movie to get to that point. You gotta have the build up. Like Flight of the Phoenix... I can't jump to the starting of the plane, even though I've seen the movie fifty times. When that engine finally catches, what makes it so satisfying is what you've gone through to get there. Gladiator's like that, and a bunch of others. Payoffs have to be earned.
The Horse Soldiers is that way for me too. My favorite part is when William Holden finally gets pushed too far and dashes his drink in John Wayne's face. And off they go to duke it out. And it gets better when Holden asks him what the rules of the fight will be, and Wayne says "Just make up your own." So Holden slugs him on the spot. Very satisfying. Alas, their fight is way too short, interrupted by battle, but that just leads us to an even better scene, when Wayne gets shot and Holden gets to treat him. Hah. I love it.
The rest of the film has nicely spaced action scenes, cool scenery, a catchy main theme that I will find myself singing for the next two weeks after a viewing of it. I love that the love story is understated, that it just happens quietly, almost in the background, the characters conveying emotions with looks and actions more than words. I love that William Holden stays behind with the wounded soldiers at the end. And I really love the Wayne/Holden actor combo. They sell this story to me.