"Every post is a self portrait of its poster" - someone somewhere has that line in their signature, and I've always agreed with it. There are other indicators about a member of a forum, but there is no better measure than the composition of each post.

I like having set titles though as well. The signature is the logical personalization area, so if the title area doesn't serve a distinct purpose, it kind of serves no purpose in my mind. Not that its a big deal - some sites let users set them themselves, and that works too. A little fun is good, but when it comes to forum layout stuff I tend to think like Spock.