If you are on a tight budget, this Tart Tank will fit the bill. It's a popular choice, while not very pricey.
For something in the middle of the price range, consider purchasing this Eberjey Tank. While the price is very reasonable, this piece is an easy wardrobe update. It's also worth taking a look at this Joie Tank. This product is ultra popular and, just as importantly, not too pricey. Alternatively, opting for this Cotton Citizen Tank is a smart choice as well!
If you can afford it, then you absolutely must check out this Joie Tank. This piece seems expensive, but it's worth it. Why not take a look at this Akris Punto Tank too? Expensive, but worth every penny. And how about the luxurious Shoshanna Tank? Yolo, right?