I've watched my way through about half of Warner Gangsters 1- the Roaring Twenties, Little Caesar, and the Petrified Forest, so far- and far and away the one I've enjoyed most of the three was the Petrified Forest.
Little Caesar had a pretty great Robinson performance, but the rest of it ranged from odd to dull, with the exception of a few highlights. The shootout that opens the movie and the big robbery were both interestingly presented, but other than that, nothing really grabbed me. The famous ending line seemed immensely odd- I feel like there was an "Is this the end... of Milhouse?" parody of it on the Simpsons at some point, but it's such a bizarre thing to say in any case that it made the whole of the movie more difficult to take seriously in retrospect.
The Roaring Twenties didn't have any obvious flaws, and I enjoyed Bogart quite a bit, but it seemed just to skim over the plot points without any especially interesting moments either visually or of character. Cagney's character seems to fall ass-backwards into his rise, his fall seems unmotivated, and his love interest seems haphazardly worked out- I never really saw the appeal. Bogart's character, who seemed genuinely friendly but also totally unburdened by conscience, seemed much the most interesting to me, and I wish the movie had stuck more with him.
Perhaps it's just Bogart fandom that lead me to love Petrified Forest as much as I did, but I think it's also the sense of characters breaking out of a preset type and showing flashes of interesting humanity- the black gang member making fun of the chauffeur for being an Uncle Tom (which I thought remarkable for a movie of the era), the spoiled rich woman pleading with Bette Davis' character not to sell herself to some dull asshole the way she did- which came totally unexpectedly out of what seemed like a stock character- and even the ex-football player, who came off as painfully rapey when first introduced, was if not a rounded character, at least an interestingly characterized one. Leslie Howard's character seemed a less interesting type, but Howard sold him well, and made me want to see more of his work- and Bogart, of course, carried the screen like no-one outside of Welles in the Third Man.
The philosophical underpinning of the Petrified Forest and its symbolic representations seem sort of dreary, but goddamn if it wasn't more entertaining and engrossing than the quick moving actual gangster pictures. To me, anyway.
edit: Dear God, is the commentary on the Roaring Twenties awful- it's got to be at least 80% just reciting what's happening in the movie, with the occasional biographical snippet tossed in if you're lucky.