I keep waiting for Pixar to run out of good ideas, and they never do. My favorite of their shorts, "Lifted" and "For the Birds", are very much in the tradition of the old Warner Brothers. The emphasis is on characterization, sight gags, facial expressions and sound effects rather than dialog, and much of the humor comes from playing with our expectations. You simply don't expect a huge "Close Encounters" alien ship to be piloted by an inept trainee on a check ride who can't even fit his captive through the window. You don't expect a highly advanced alien flight instructor to take notes with an ordinary clipboard and ball point pen. You don't expect that a would-be abductee would stay asleep through all that only to wake up when his alarm goes off.
The WB greats also discovered that the biggest laughs often come from the smallest details. When the Coyote realized that he was about to get pounded (again) by a huge falling boulder, his eyes shrank to pinpoints. I always found that funnier than the actual boulder-pounding. In "Lifted", watch the mailbox near the farmhouse when the spaceship (unexpectedly, of course) crashes. A moment later, the flag on the mailbox falls. I missed it even in the Blu-Ray version, but once the director pointed it out in the commentary, it became the funniest part of the gag for me.
The WB greats also discovered that the biggest laughs often come from the smallest details. When the Coyote realized that he was about to get pounded (again) by a huge falling boulder, his eyes shrank to pinpoints. I always found that funnier than the actual boulder-pounding. In "Lifted", watch the mailbox near the farmhouse when the spaceship (unexpectedly, of course) crashes. A moment later, the flag on the mailbox falls. I missed it even in the Blu-Ray version, but once the director pointed it out in the commentary, it became the funniest part of the gag for me.