The picture and logo that we used this year can be seen
here. The little flame-flower and number were on the front-left chest, the LotusMan took up most of the back (with "Robotics 2003" underneath it, our artist was kind of rushed) along with our sponsors' logos, and it was all blue ink on a gray shirt. Someone at the Peachtree Regional liked it so much they asked us to turn around so he could get a good picture of it, but instead we just gave him one of our extras. Next year we'll probably use something very similar, but I'm working on cleaning up the pictures a bit (like giving the flower some radial symmetry and having the guy holding his thumb to his middle finger instead of his middle and ring) and we're going to try and have our driver look like more like the LotusMan (Open EEG controls! woohoo!)
As to my favourite, I like the SPAM one because it's fairly clean and has intense colors without being too bright.