Under Armour is great for offering shelfless tanks in a variety of styles.
The ribbed Victory tank ($20) (seen here in purple) comes in eight colors and has venting panels to help keep you cool during workouts. What I love most about the tank is its moisture-wicking ability — no matter how sweaty you get, this tank will keep you dry.
Under Armour's Playoff Layer tank ($28) is also made from moisture-wicking materials but scores major points for its fashion sensibility. It's light and breathable, and, if you're feeling self-conscious about your body, you'll love that it doesn't cling.