My favorite Western film?
ALL OF THEM!
I'm completely indiscriminate; I love them all, good bad, indifferent, comic, tragic. If it's got cowboys and horses. I love it.

OK, except the Wm. Shatner one, which I've seen; but then again, it's so bad it's good.

Now a new thread or change the direction of this one:
my favorite TV westerns: The Range Rider starring Jock Mahoney and Dick Jones; Bronco starring Ty Hardin; Gunsmoke with James Arness et al; Maverick with James Garner, Jack Kelly and Roger Moore; and loads of others.