The Mexican Hat is very easy to get to and there are good roads around it so you can get good views from many angles.
It is best in morning and evening with clouds in the sky. In the late spring the vegetation behind the hat turns green and this is ideal.
Its a little hard to get to...but well worth the effort. The Rock Factory is a really cool place overlooking Lake Powell. Its right off HWY 89 on the way out of Page AZ headed to Kanab.
Not far from Page and best shot in the morning or even better in the evening with clouds in the sky. Some say that a thundery atmosphere in the late afternoon is just excellent for taking photos.
Tips for morning / afternoon shots: The rim blocks the best light until about an hour after sunrise. At sunset the rim also blocks the best light but not as much as after sunrise.