Yup, just bought this a couple months ago:
Zinus Memory Foam 12" Queen.
I was a little leary of ordering it online (haven't done it before) but it turned out fine and I'm glad I did. It came quick (Prime shipping) and I took it out of box and let it inflate to regular size. I waited like 48 hours or so but you could probably wait 24 hours. I have noticed that one or two of the corners isn't quite inflated to 100% but it's not really a big deal and there's no way I'd return it just for that. With the sheets on you really don't notice it anyway unless you're looking particularly for it.
My only "complaint" would be that the memory foam mattress sleeps hotter than my old crappy spring mattress, but it was mainly due to the mattress protector I had on the Zinus. Still, it's warmer than my old one, but not quite as bad as it was with the protector on it. On the other hand, it's much more comfortable than my old mattress and I no longer wake up sore.