T-shirts form the foundation of a man's casual wardrobe and run the gamut in terms of silhouette. Classic crew-neck and V-neck designs complement both short-sleeve and long-sleeved styles which come in plain colors —such as white, black and blue— as well as multiple patterns such as stripes and florals. Whether worn under a suit with dress shoes or with jeans and sneakers, a T-shirt is an basic that defines staple style.