Sheldon Coopers 'Superman Grungy Man of Steel Shield' Shirt
Here's what's probably the most modern looking Superman shirt that Sheldon has worn on The Big Bang Theory (so far). As the title suggests, the design is of a grunge style with a metallic looking Superman "S". You can purchase it by using the Amazon link below.
Featured on The Big Bang Theory episodes
S09 E09: "The Platonic Permutation" S10 E21: "The Separation Agitation"