Grant and Peck are my two favorite Old Skool actors. Grant is a hideously underrated comic actor.
Rear Window and North by Northwest have always been my favorite Hitchcock films. Sure, they're low-hanging fruit, but Grace Kelly and Thelma Ritter KILL it in the former and Bernard Herrmann's score and Eva Marie Saint's sensuality dominate the latter. Plus, James Mason is another of my favorites.
Those aside, Rope is Jimmy Stewart at his best. Some dizzying overacting by the two other leads, however. It was Hitchcock's first color feature and, gimmickry aside (the continuous shot conceit), it's a masterful one-room film. Leo Carroll in this film and Cedric Hardwick in North by Northwest have two of the best Hollywood voices of all time.