I'm not going to rain on anybody's parade. This is a terrific movie, and lots of other reviewers have already ticked off all of the things that make it terrific. It's smart and sophisticated, with plenty of witty dialogue. Although some of the details are dated, such as the interminable rows of pencil pushers at desks with adding machines, the underlying office politics are just as real and just as nasty today as ever. The acting is great. Not only are Lemmon and MacLaine wonderful together, the rest of the cast is also excellent.
The only thing I have to add is that, despite clever lines, funny scenes and an acceptably happy ending, THE APARTMENT is as much a drama as it is a comedy. The seamy undercurrent of office politics and the way people ruthlessly use each in their personal relationships gives this little tale a grim, almost vicious, feel at times. Much of what you see in THE APARTMENT is not the least bit funny.
Not to be repetitive, but this is an outstanding movie. If you haven't seen it, you should. It's not really a family movie, though. True to the period in which it was made, there's no overt sexual content, but there are definitely adult themes and kids probably wouldn't fully "get" what's going on, anyway. Be that as it may, THE APARTMENT would be a great addition to almost any classic movie collection.