I really, really liked this movie. Not only is Jake Gyllenhaal super cute as the bumbling cartoonist/code-breaker/amateur sleuth, but Mark Ruffalo stars in this film as the super cute detective/cop who he teams up with to try and find the Zodiac killer. Robert Downey, Jr. has a good role, too, but I like Gyllenhaal and Ruffalo best. Although, Dermot Mulroney does have a small part in this, and he is quite sexy (even with the small gut).
Despite the fact that this movie seems to last for the twenty some odd years it covers, it's really good. A lot of research, a lot of suspense, a lot of drama...great murder mystery movie. The fact that it's based on true events makes it even better! It frustrates me that they were so close for so long, and it's amazing that people actually spent the massive amount of time they did researching the killer, trying to put everything together. It would have been sweet if they could have actually caught the killer in the end and had justice served, but you can't win them all...which sucks. Still, excellent movie!