Hi Destro,
Unfortunately it isn’t possible to put together a list of this type which would have any meaning or relevance for any individual person.
There is no such thing as the “best mattress” or the “best manufacturer”, or even a top 5 or 10 or even 100 (see here and here and here) … only a mattress that is “best for you”. A mattress is too individual a choice and there are too many individual criteria and personal preferences involved for anyone to know which mattress is best for someone else based on specs (either yours or a mattress) or “theory at a distance” (see mattress firmness/comfort levels in post #2 here).
Outside of PPP (Posture and alignment, Pressure relief, and Personal preferences) which is the most important part of the “value” of a mattress purchase … a mattress is only as good as its construction and the quality of the materials inside it regardless of the name of the manufacturer on the label and “brand shopping” is among the worst ways to choose a mattress because the name of the manufacturer won’t tell you anything about whether a specific mattress is suitable for you in terms of PPP or whether there are any lower quality materials or weak links in the design (see post #5 here and post #12 here).
The mattress shopping tutorial has all the basic information, steps and guidelines you need to to know “how” find “your” best mattress and as you are suggesting this is the best place to start your research.
Post #13 here also has more information about the most important parts of the value of a mattress purchase that can help you make meaningful “value” comparisons between mattresses regardless of the brand.
There is also more in post #2 here about the different ways to choose the most suitable mattress (either locally or online) that can help you identify and minimize the risks involved with each of them.
Once you are over about $3000 (queen size mattress only) or the equivalent in other sizes I would make sure that you do some VERY careful value comparisons between mattresses because higher prices may have very little to do with how well you sleep on a mattress or the quality and durability of the materials inside it (see post #2 here and post #2 here).
The Houston list will help you narrow down your choices and you certainly have some good options available in the area.
Phoenix