I watched the 1941 version of Dr. Jekyll and Mr. Hyde starring Spencer Tracy. Then I watched the 1931 version of Dr. Jekyll and Mr. Hyde starring Frederic March.
I thought the 1941 film was excellent. Tracy is absolutely superb in his dual role, playing the tortured scientist with the right blend of self-restraint and impatience, then really letting himself go as the unfettered maniac Hyde. I was amazed at how risqué, given the epoch, some of the scenes were. For example, when he first takes the potion, Jekyll has a brief dream full of wild imagery, representing all his repressed desires: at one point he's riding a carriage, laughing uproariously and whipping the inflamed horses. Then the horses are gone, replaced with the two women in his life --- they are drawing the carriage, and he's whipping them and laughing. Later, a seduction scene involving garters and a lot of exposed legs seemed to me, for the time, quite daring.
At first the 1931 version didn't hold my interest. Frederic March, of course, was an actor of his era, made up and hamming it up like he was on the Vaudeville stage. But soon I realized that the 1941 version is a completely faithful remake, scene for scene, of this earlier classic film (this made me revise my opinion of the later movie a bit). Yes, there are very awkward moments early on, such as the chemistry-free wooing scenes between March and Rose Hobart, his fiancée, replete with awkwardly close face shots, stilted dialogue and expressionless proclamations of love while one's nose is practically squished up against the other's.
However! March's performance grew on me, especially after he turned into Hyde. The makeup was a bit distracting (he looked like a cross between Grandpa Munster and Eddie Munster --- Hyde's not the Wolfman, for pete's sake!), but I suppose representative of the novel's intent to represent Hyde's moral evil physically, "giving a strong feeling of deformity." And March throws himself into the bad guy role, breaking out of his textbook Thirties Leading Man Type restraints and coming off almost frighteningly evil, even to the modern viewer.
And this version, too, wowed me with its risqué scenes. At one point, Miriam Hopkins (who plays doomed Ivy, object of Hyde's cruel lust) actually appears to be naked under the covers, which surprised me. She, too, shows a lot of gam in Jekyll's seduction scene. I didn't know the studio bigwigs allowed that kind of thing. A real old movie buff would know more than I about what was acceptable then.
In all, I have to give props to the 1931 movie for its terrific adaptation, March's joyously evil Hyde, and its apparently boundary-pushing subject matter. However, I'm a big Spencer Tracy fan, and I think the 1941 film's screenplay tightens up the drama in a few key ways (though it gets points off for lack of originality: not only are the scenes exactly the same and in the same order, some of the dialogue is taken from the March movie).