If I could only recommend one product for overnight hiking, a Therm-A-Rest mattress would probably be it. Lightweight, compact, comfortable, insulating, and convenient are all features that make this mattress a must-have:

Lightweight: My ProLight 3 weighs only 1lb 4oz

Compact: it rolls down to 4.5"x11"

Comfortable: I still can't believe that a 1" thick mattress can be this comfortable. But, unlike with a foam mat, I don't feel the ground at all.

Insulating: Because there is a foam core that provides insulation, the Term-A-Rest is considerably warmer than a non-insulation air mattress.

Convenient: Just open the valve and stand back while it self-inflates. A few puffs to firm it up and your done. I used to spend a half-hour blowing up air matresses.

-sdr