Sometimes editing, good or bad, draws attention to itself. I think the editing in Memento is good, but you certainly notice it. So I wouldn't necessarily say the best editing is the editing you don't notice. Ali isn't poorly edited; in fact, I'd argue that the opening sequence, with Sam Cooke singing and Cassius Clay beating Sonny Liston, is beautifully edited. The story editing is off, though ... scenes we don't care about go on forever, scenes we want more of are over before they get started (or, at times, aren't in the movie at all).
Of course, most people who know me are aware that I think many, many movies today are too long, so I certainly agree with Sue that Ali could be a lot shorter. I'd rather be watching Booty Call.
Waking Life is too long and too short at the same time. At times while you're watching it, you wish a particular character would shut the hell up, but you're not really antsy, because you know someone else will come along in a minute or two, and maybe you'll find them interesting, and maybe they'll be gone before you've had enough. I usually mistrust films that beg to be seen again, movies that as soon as they're over you need to watch them from the beginning in order to actually understand the fuckers. But Waking Life makes you want to watch it again because it's such an intelligent, heady mix of ideas that you want to hear them again, to mull over the best ones and reconsider the worst ones. The movie is both elitist and populist; actually, it's neither, it just stands those terms on their heads and makes them irrelevant. You have a bunch of people talking about deep philosophical topics, and some of the people are among the elite of their field and some are just average Joes or Janes, and some of them are on target and some are full of shit, but there's no direct correlation between a character's standing in their field and their level of bullshit. Some of the sharpest characters are Joe/Jane Average; some of the most overblown are "professionals." And some pros are sharp, and some Joe-Janes are loony. Categories are worthless in this film.
As for the look of the film, it is one of the best visual approximations I've ever seen of tripping. OK, of dream states ... all I can say is my dreams don't look like Waking Life, but the world under the influence of LSD looks and feels a lot like the imagery in the movie. It gets that "weirder than real yet somehow more real than real" feeling down perfectly.
Read the reviews for this movie and you'll notice the film's fans make a good case, while its detractors don't get much beyond "don't like it." Which is a perfectly valid response, but in this case, the intensity with which the movie's proponents engage its ideas is telling. This is a very smart movie that has the potential for broad appeal. That's a good thing. I give it an 8 on a scale of 10, but I bet if I ever watch it again, I'll give it a different rating, depending on where I'm at then.