Nah, I just use them to remember people. I tend to recognise people by their avatar rather than their username. For example take the first couple of posters in this thread. I'll remember the user with the Bruce Wayne in a suit avatar as a cool guy and the guy with the Saxophone meme avatar as one to avoid.
I have to say that when I go into a thread and 90% of the avatars in the thread are anime avatars it definitely sets the tone for the thread. Not for worse or for better.