Hmm... Well Spike Lee films always require a couple viewings to really understand the intricate details of what he wants to portray, but when you do, you realize it's a good film. As for 25th hour, Spike Lee mentions that he made this movie as a reaction to NY/America in a post 9/11 era (it's also pretty evident in the movie). Not to say that Ed Norton's character is a symbolism of NY or America (although there are some overlapping ideas about how he is searching for a truth, or the source of his ill situation), but more of Spike's observations and reactions of what had happend and how the citizens of America reacted.
Something wrong happend to us simply because we were betrayed and made us feel vulnerable. And in many ways we became cynical and obsessed with what happend that day, and how that day not only showed us our vulnerablity but allowed us to see ourselves in a new manner (much like the main character at the end of the film) but that's just my take on it. Either way, I thought th movie was pretty good.
Sometimes his movies are hard to understand unless you know NYC relatively well, partially because of the language and mostly because the settings he uses for his scene have really stronger specific relations to the film than what general directors do.