We have a Tempur Pedic. We liked it when it was new, but it hasn't lasted as long as we'd hoped. I seem to sink right down into it to the firmer core now, and get a pressure point on my hip when I lie on my side. Also, it's hot. Not a great compliment to hot flashes.
We're considering a new mattress right now and have been looking at the "next generation" memory foam mattresses at Sears. They supposedly don't get as hot. We'd love to get a mattress we encountered in a hotel room once, but when we took the details and model number to a furniture store, we were told that it was only available to hotels and not to the public. Oh well.