If you're not planning on spending much, why not look at this Hanro Tank. It's a fantastic product for a good price. You might also be interested in this Vimmia Tank. It's an item you'll fall in love with which also doesn't cost a fortune. You might also want to consider this Cotton Citizen Tank. The price is very reasonable, but the effect on your wardrobe will be pretty fantastic.
For something in the middle of the price range, look no further than this Feel The Piece Tank. This item doesn't cost a fortune, but definitely deserves a place in your wardrobe. It's also worth checking out this Frame Tank. This item is extremely popular and, just as importantly, not too pricey. And do check out this Eileen Fisher Tank! It's a very popular item and good value for money.
If you're looking at it like an investment piece, why not check out this Rag & Bone Tank - a great luxury choice. While you're at it, also have a look at this Dolce & Gabbana Tank. Yes, this item is expensive, but it does not mean it's not worth it. Also look at this Tibi Tank. You won't regret the money spent!