Spike Lee, and have always thought his movies are somewhat overrated, but in Summer of Sam he gets everything right.
Adrien Brody is a very talented actor who doesn't get nearly as much praise as he deserves. While this might not be his greatest role ever, I always appreciate seeing him on screen. John Leguizamo is also a guy who's slick smile is always contagious, and his desperate tantrums are always amusing.
What makes Summer of Sam really interesting however is that it's a serial killer movie, where neither the serial killer, nor the anti-hero trying to catch him is paid any attention to. Instead we get to see how the knowledge of a serial killer lurking around your neighborhood, affects the people who are trying to live normal, everyday lives.