Big Bang Theory Friendship Levels T Shirt Even a creepy guy like Howard Wolowitz has friends. Of course, he places them in a strict order, beginning with Raj, the best friend, followed by Leonard the secondary friend, Sheldon the ?slightly apathetic tertiary friend,? and Penny the ?oblivious but hot quaternary friend? who Howard would love to elevate to No. 1 if he had the chance. This Big Bang Theory t shirt offers an amusing take on the ever-evolving friendships that are central to this hit TV sitcom. The Big Bang Theory Friendship Levels T Shirt is silver with deadpan portrait shots of each major cast member.