If you're not planning on spending much, your best bet is this Eileen Fisher Tank. It's a terrific product, while not very pricey. Another strong contender for your wardrobe is this Ralph Lauren Tank. While the price of this piece is competitive, it will definitely attract a lot of attention. You might also want to consider this Ming Wang Tank. The price is very reasonable, but the effect on your wardrobe will be pretty fantastic.
If you're looking for a good deal, look no further than this Vince Tank. This item doesn't cost too much, but absolutely essential in your wardrobe. Also consider this Eileen Fisher Tank. It's an attractive option both price and quality-wise. Consider this Misook Tank too! Great value for your money.