Often times a great outfit can fall short of its potential due to one simple oversight: the undershirt. With the Banana Republic No-tag Stretch Crew ($22; 3 or more $18 each) you can rest assured that won't be a problem again. We've been wearing them for a few weeks now, and they keep you super comfortable with a 95/5 Cotton and Lycra blend, and feature a 1x1 rib trim to make sure they retain their shape underneath the tightest of dress shirts and tees. $22 for an undershirt seems like a lot — but we think it's worth it.