Roadrunner, my favorite motorcycle magazine, has a trademarked monthly feature called a Shamrock Tour; they find a central location from which they can take three or loop trips through interesting and scenic areas.
Last year, we tried the same concept on my bike - we were looking for a central location so my wife could enjoy herself reading or shopping (she doesn't ride) while I took two or three nearby rail-trails, or bike paths in the town. We picked Mankato, Minnesota, Sparta, Wisconsin and Des Moines, Iowa, alll were good choices since they allowed me to ride during the day and enjoy the afternoon and evening with her.
I've checked the Rails-to-trails conservancy's pages and their Traillink.com online guide, and am looking for suggestions and hints from others of other good places to visit,
Ideas?

High Trestle Trail north of Des Moines
P1030217 on Flickr

Sparta-Elroy trail, Wisconsin
P1030295 on Flickr
P1030243
Sakatah Springs State Trail, Mankato, Minnesota on Flickr