The red theme gives me great nostalgia of the old days...Not to mention the simplistic red/white look makes this forum relaxing to be in...or something.
I got to check the other skins though.
For the affiliate button, I appreciate the whole "It's a trap!" thing with the CP quite a lot. Now how many people will realize this is an RPG Making Community... :v
EDIT: Oooh...the blue is definitely relaxing.