If you're on a thrifty budget, your best bet is this Hinge Tank. It's a terrific product, while not very expensive. In this price range, you can also consider this James Perse Tank. It's also a popular item and won't break the bank. Or you can opt for this Tank. This item has all the potential to become a powerful player in your wardrobe.
If you can afford it, then what you're looking for is this The Row Tank. It's more expensive but worth your money. While you're at it, also have a look at this Joie Tank. Yes, this item is expensive, but it does not mean it's not worth it. And one more item you might be interested in is this Chloé Tank. 'Cause you deserve nothing but all the finer things!