willybfriendly - 11:31 pm on Jan 9, 2011 (gmt 0)
North Cascades NP. Not on the list yet. Beautiful scenery, and if you get off the only through highway very secluded as well.
Also in the PNW, Crater Lake is a must see, although a single day is probably sufficient for it (assuming it is not filled with clouds on the day you visit.)
Death Valley is great in the winter, as is most of the desert.
Little known and seldom visited it seems, check out Taos, NM. Ask the locals for the name of the resaurant that serves avacado pie for desert - unique and scrumptious (I can't remember the name, although I could take you to it.)