Here's the breakdown to choosing the best memory foam mattress.
1) Traditional Memory Foam Mattresses
Tempur-pedic, bob-o-pedic, chinese o pedic etc.
You have different qualities to everything in life. The same goes for memory foam mattresses.
Made in the USA, Europe and Asia are pretty much your options. Qualities vary in each.
Judge a memory foam mattress by its density. The HIGHER the density the longer lasting the foam. Anything over 4lb density and you're looking at a good quality memory foam.
The density for all layers must be taken into account! No point having the top layer last 20 years if the bottom layer is only going to last 10 years right? Typically that's how they trick you. The salespeople only talk about the higher density foam and choose to ignore the cheaper foams the mattress is primary made with.
Chinese foam mattresses are as sketch as they come. It doesn't take people to make foam, it takes ingredients. So who knows what they're putting in there to get those rock bottom priced queen size memory foam mattresses.
Mattresses are NOT tested when they come into the county so who knows what these Chinese memory foam mattresses are made of.
2) Eco Memory Foam Mattresses
Building in popularity these eco foams are the industries answer to people wanting to GO GREEN.
Eco-Friendly memory foam mattresses are made from the same ingredients as all other memory foam mattresses but they include 5-20% soy, castor oil or cedar oil. It's a greener way to go but not necessary a healthier way to go since its only 5-20% healthier for you.
3) Natural Memory Foam Mattresses
There's only one company claiming to have natural memory foam and that's Essentia. Their memory foam mattresses are made from rubber tree sap instead of petroleum based chemicals. Basically they are the only natural alternative to memory foam. Their memory foam mattresses are more breathable (they don't sleep hot) and aren't' as temperature sensitive as traditional memory foam mattresses. See how they compare to Tempur-Pedic.
It really comes down to budget. Just make sure you choose a quality memory foam mattress with a high density!