Hey-
I'm partial (very biased) to the Black Hills of South Dakota. I worked on these waters for four years and I love 'em. You've got reservoirs, tailwaters, spring creeks and freestone streams all within an hour of each other. Access is easy, but pressure is minimal. The hills are often overlooked by people on their way to more famous waters in Montana and Wyoming. Spearfish Canyon is a place that's unforgettable. Also, the Black Hills are very close to the Bighorn River, the North Platte and the Bighorn Mountains. Take a trip here and you'll be very pleased. There is plenty of lodging and plenty of tourist stuff to boot. There's a fly shop in Rapid City with good info (and the guy who owns it is named Hans.)
www.flyfishsd.com
Jamie