That's a really good question. It depends. SFW Flicker hates clothing with a passion. Man would love nothing more to spend all day, every day in the fur. If he needs to wear clothes, I think it's typically a dark green hoodie with really thin yellow stripes that look like laser beams, and black jeans. This is what he'll wear for dealing with something serious.

Flicker the nerd I think is typically wearing black jeans and some kind of T-Shirt, probably plain black, and of course a variety of cartoon underwear. No shoes either way though.