Another very hard choice, as I have loads of favourites, and a lot depends on what mood I am in. I love 40/50's films ... musicals especially. And I have favourite actors like Cary Grant, Doris Day, Danny Kaye,etc. I do also love Will Hay films and The Marx Brothers films ... yes, I'm a bit mad!
Some of my favourite films are -
Guys and Dolls
Arsenic and Old Lace.
The Secret Life of Walter Mitty.
Fiddler on the Roof.
Carry on ... Up The Khybur/Screaming/Cleo
Passport to Pimlico
etc
And, of course, one actor I must mention is James Marsters. I love all his work, but am especially fond of Moonshot, as I remember standing in our back garden watching Neil Armstrong and Buzz Aldrin on the moon! (I do also love Appollo 13, which never fails to grip me with the story)