I have a herniated disc from a injury when i was young. Over the years, I have tried every type of bed out there and found them all uncomfortable.
For the past 2 1/2 years now, been sleeping on Serta Raised Air Bed with Never Flat Pump. Has not gone flat or punctured so far and i sleep on it daily.
It's the most comfortable sleep thus far and easy to move/clean under. Don't over inflate it or the seals will leak, learned this the hard way.
http://www.amazon.com/Serta-Raised-Q...dp/B006OU4IQC/
I actually have one of those from several years ago in college. Mine is probably a different brand, though, but it looks pretty close to the one I have laying around in a box somewhere. I slept on mine for 6 months or so, worked well for the $80 mine was. Just have to watch for pets though; my roommate at the time had a cat, but I kicked it's ass whenever it got close to the bed.