Well, "outside of Houston" could include the entire planet, yes? I hear it's very nice in Tuscany, but have never been there myself.
/ kidding...
A couple of tips:
- the mapping sites like mapmyride.gom and ridewithgps.com have useful search functions so you can find routes that others have mapped / pedaled.
- within "day trip" distance, the Bastrop State Park - Buescher State Park loops are excellent; the National Forests have some nice quiet pretty roads, And the area North of Palestine has some amazing backroads with nice hills.