Hi coolmonk,
The first place i would start your research (in case you haven’t read it already) is mattress shopping tutorial here which has all the basic information, steps, and guidelines you will need to make the best possible decisions.
There are too many variables and unknowns in your choice of materials and mattress designs for anyone to put together a “top 5” or even a “top 100” list out of all the many thousands of mattresses that are available in the industry that would have any meaning. Shopping by brand (instead of based on your own personal testing and on the quality and durability of the materials and components in a mattress) or based on other people’s recommendations that may have very different needs and preferences is not generally an effective way to choose a mattress. mattress firmness/comfort levels in post #2 here talks more about the importance of your own personal testing, preferences, and research and will help you narrow down your choices to your own “top 5” that may be very different from anyone else. Nobody else can feel what you feel on a mattress or know with any certainty based on “theory at a distance” which mattress will work best for your unique needs and preferences … especially without some reference points based on your own testing experiences on different types of mattresses.
Phoenix