Pine - $
Most pine you get at the big box stores is considered white pine, common pine or SPF (Spruce, White Pine or Fur) that is soft and needs a lot of care when kept outdoors. Tends to have knots and other blemishes and has a tendancy to warp or twist over time.
Cedar - $$
Western Red Cedar is known for its ability to resist rot and decay and since it absorbs and releases moisture very easily it has an added benefit of resisting splitting, cracking and warping like other woods. It does require more maintenance to keep its natural appearance but does tend to turn silver/grey after time.
White Oak - $$$
White Oak is comparable in hardness and durability to Teak and Cypress while still at the same time being some what more affordable than Teak. A very heavy and strong dense wood most commonly used for whiskey barrels. It takes stain very well but also looks great finished with tung-oil.