My gripe about RENT was over the pretenciousness of the advertising. Since I've never seen it, I couldn't tell you if it was better that Chicago. It does, however, have a number of things working against it:
-Its set in the year 1990. I hated that year, as it did suck whole-heartedly.
-"No day but today" is just a retarded slogan. Period.
-Here in 2005, AIDS isn't considered the threat to western civilization and the end of life on Earth that is was back in the late 80s/early 90s, so the films relevance is pretty low.
You do realize "Chicago" was satire, right?
Given the heights that sensationalism in journalism has reached lately, if viewed as social parody, "Chicago" is far more relevant comment on modern society than the more-contemporary "Rent".