I've had a queen size bob-o-pedic(Bob's Discount Furniture) for 10 years that I got as an overstock from The Pit for $350 with a box spring and it has been the best mattress I've ever owned or slept on. I believe it is the medium firmness. I have a spill proof cover on it that I have replaced a few times, but the mattress itself has not show any wear in comfort.

I know everyone's taste is different, but worth checking out.