Depends on what you like. If you like Ranch style focus on them, if you like Cape Cod then look at those. You'll also have to decide what you can or what you want to afford but ultimantly you'll want to consult with your real estate agent when that time comes.
First and foremost, you want to own the one that you can afford. Then you want to own the one that meets your physical and emotional needs. Only after those criteria are met should you add your "wants and wishes".