Amid Amidi of Cartoon Brew put up this animated GIF that compares two shots from the opening of The Simpsons: the first from the opening that was used from 1990 through most of the ’00s, and the second from the new opening that was created when the show switched to high-def. The new opening is one of the better parts of the current show, but the earlier version was better-animated. Not necessarily because of any inherent difference between traditional cel animation and digital, but just the amount of personality and acting that goes into it. Part of this is a directorial choice, since in the second version it was decided to have Marge not react to Maggie popping out of the bag. But it’s also just a question of animation style; the first version has more flair and “bounce” to all the movements — Marge’s, Maggie’s, even the bag — while the second version is pretty standardized even on the one bit of physical acting (Maggie shaking her fist at the one-eyebrowed baby). The older version has the obvious drawbacks of cel animation, particularly the fact that perspective is hard to do; the ceiling doesn’t exactly look like a ceiling. But Marge and Maggie have physical personalities in the 1990 version that they just don’t have in the later version.
The opening, of course, is the part they spend the most money on, so the animation of Marge in the 1990 opening is “full animation” in a way that the regular episodes couldn’t afford. Still, the animation on The Simpsons through much of the ’90s was generally better in that important respect — physical acting — than it became. This has nothing to do with digital, because the animation was getting stiffer toward the end of the ’90s. It’s just a question of the number of unusual or character-revealing poses. The show can’t be too cartoony (the original pilot was sent back for retakes because the animation was too broad), but within the more subdued style it can still have lots of great cartoon acting. As this post on “Homer Goes To College” highlights, as late as season 5 there were episodes where the drawing enhanced the humour or revealed character. Even in the movie, which was certainly well-animated, it’s hard to find that kind of funny drawing.