The Apartment is a great drama-romance-comedy classic excelling with the performances by Jack Lemmon (at his absolute best IMO) and Shirley MacClaine, set against the sharp script and direction from Billy Wilder.
The Secret Life of Walter Mitty is a film with so much potential squandered for the sake of a buck using blatant in-movie advertising but instead of furthering the story, they only served to take one out of the film despite some good performances, particularly Ben Stiller and Kristen Wiig, with honorable mention for Adam Scott for playing one of the biggest/best cinematic douchebag.