Fatmat and Dynamat original are both ruberized asphalt. Fatmat is just like peal n seal basically. Skip it. Go for the original Dynamat because it's heavier and thicker, however it doesn't have the viscoelastic properties as butyl.
All the butyl prodicts work nicely. RAAMmat is never a wrong choice, but Dynamat Extreme is great if you can get it for cheaper.
power-mat is a joke. A budy of mine bought some and he put 2 layers in the inside of his trunk area and it still rattled like a *****. Didn't even deaden the area. He switched over to some Second Skin Damplifier Pro and that sum ***** doesn't hardly flinch at all.