Try Casper for up to 100 nights, risk-free: http://kadavy.net/casper/
(No coupon or promo code, just click the link!)
UPDATE: I was worried about this mattress after the first night: woke up with a sore back, BUT, I've slept on this mattress about 5 nights now, and am really happy with it!
I wrote a little more about the Casper over here: http://kadavy.net/casper-review-coupon/
---
The Casper mattress consists of a 1.5" layer of latex foam over the top of memory foam. So, it contours to your body very well, but still has a nice bounce to it.
I was putting this mattress on an IKEA Malm Full bed frame. I was reluctant to order the Casper because my IKEA frame is one inch more narrow than standard, but it hasn't been a problem at all.
Read more here: http://kadavy.net/casper-review-coupon/
