I don't know if I could say Texas is underrated, if only because of its size and amount of golf courses. And it has a swing on the PGA. When I think of underrated I think of the states you almost never see on TV. And in that case, I'm going to put out Colorado as a nominee. Not only do you have some of the oldest and top-notch resort courses (Castle Pines, Cherry Creek, the Broadmoor) you also have well-respected public, private and military courses that are bar none in terms of condition, layout, and of course, views! I'm thinking courses like The Air Force Academy Blue course, The Country Club of Colorado, the only Nicklaus public course in the world outside Breckenridge, Walking Stick, Patty Jewett, and many new courses in the mountains and western slope I admit I don't have the names for. Castle Pines is the only tour stop and every generation there is a major played somewhere in Colorado, but besides that, there is little national recognition for the state. Its a pity. And with the altitude, you get your ego stroked on drives!
steve