If you are on a budget, your best bet is this The Limited Tank. It's a great product, while not very costly. In this price range, you can also take a look at this H&M Tank. It's also a popular item and won't break the bank. You might also want to consider this Spiritual Gangster Tank. The price is very reasonable, but the effect on your wardrobe will be pretty fantastic.
If you're willing to splurge, why not check out this Christopher Kane Tank - a great luxury choice. Why not take a look at this Tank too? Expensive, but worth every penny. And one more item you might be interested in is this Carven Tank. 'Cause you deserve nothing but all the finer things!