I would have to say that Monster Power is both of what you have listed. It's quality stuff, but it's also overpriced and over-marketed. Richard Gray and Audio Magic are more esoteric companies that also charge a lot of money for products. I personally believe that power conditioning is strictly a science, and thus those companies that devote time to R&D should have the best products.
So, I would suggest a product from Tripp-Lite, APC, or Panamax that fits your budget and your current needs and go with it.