There is always a meaning to the logos of certain brands.
Does Super User have a meaning to its logo? Take consideration of the look of it.
It represents a (happy?) face, presumably that of the user.
There was a competition run in 2009 when the original trilogy (Stack Overflow, Server Fault and Super User) were created to design logos for the sites.
The final winner we decided on was Mogeek, with entry #425 (a late entry!). What I liked about this logo is its simplicity, while simultaneously referencing both the classic Mac OS “face” icon, and old-school ASCII art. This entry was consistently cited by my designery pals (and even Joel himself) as one they liked.
I have to say I like this a lot more that the two runner ups (and it would have been a lot harder to create an icon from the logo):