I have this in Cal King, from Costco. I waited for it to be on sale. Saved several hundred $$, and they have more in-store than usual.
They have many varieties of thickness, firmness, and layers. The Comfort Grande is what was on sale.
Novaform 14" Comfort Grande Queen Memory Foam Mattress
Features: 3" Gel Memory Foam, 3" Air Channel Foam, 8" Base Layer Foam
http://www.costco.com/Novaform-14%22-Comfort-Grande-Queen-Memory-Foam-Mattress.product.100150123.htmlI also have this gel topper for a thicker gel layer. Cooler temperature, and adds more softness. You can usually find these on sale at the same time as the mattress:
Novaform ComfortLuxe® Gel Memory Foam Mattress Topper
Features: Adapts to your body for pain free, deep sleep, 10-year, limited warranty
http://www.costco.com/ProductDisplay?storeId=10301&catalogId=10701&langId=-1&partNumber=100115178If you want to try the topper, they will let you return it if you like. Same for the mattress.
The topper does increase the depth of the mattress, so your sheets have to be the extra deep corner type.
My daughter this mattress and topper combo for a couple of years, and when my mattress needed replacing, I went with the same. Very happy with it.