Therm-a-Rest makes the most-recommended self-inflating sleeping pads. This type has soft foam bonded to the inside of a fabric cover, which is then inflated for extra loft. One or two valves are located at the foot end, and when the valves are open, the pads start to self-inflate. You can blow a little more air into them to adjust the support to your preference.
Some campers find it tricky to learn how to deflate air-and-foam sleeping pads for packing, but once they figure it out, they're easy to use. The fabric isn't puncture-proof, but we found very few reports of leaks. One thing to keep in mind is that self-inflating sleeping pads should be stored inflated between camping trips.
More reviews recommend the one-inch-thick Therm-a-Rest ProLite 3 (*Est. $85) than any other sleeping pad. It's even lighter than the Therm-a-Rest UltraLight that it replaces, and compacts to a smaller size. A women's version of the ProLite 3 adds insulation in the torso and feet, but by cutting the length from 72 to 66 inches, the weight stays at 20 ounces.
Its sibling, the ProLite 3 Short (*Est. $75), is 47 inches long, designed to minimize weight for backpacking. The Short version of the ProLite sleeping pad weighs just 13 ounces, but reviews favor the full-length ProLite 3 Regular, even though it weighs seven ounces more. The Therm-a-Rest ProLite 4 (*Est. $95) is also similar, but inflates to 1.5 inches thick and adds cushioning at the shoulders and hips, where users say they need it most.
All these ProLite sleeping pads have a textured surface to help keep sleeping bags from slipping off their narrow 20-inch width.
If budget is a bigger concern than backpacking weight, the 2006 edition of the Outside Magazine Gear Guide recommends the Therm-a-Rest Trail Lite (*Est. $60) as a "killer value." The Trail Lite is the same 1.5-inch thickness as the ProLite 4, but weighs eight ounces more. It comes in two widths plus a women's version.
Pacific Outdoor Equipment also makes some widely recommended self-inflating sleeping pads. The mummy-shaped AO Lite Regular (*Est. $75) replaces the InsulMat Thermo-Lite, recommended as a Backpacker Magazine Best Buy in 2006. (The AO stands for "All Out.") The AO Lite has the same one-inch thickness and weight as the Therm-a-Rest ProLite 3, but is bordered by extra-large tubes on each side. Field testers confirm that the tubes not only help you stay centered on the pad, but also offer welcome cushioning to the elbows and forearms. These side tubes also have some synthetic fill inside for extra warmth.
If weight is your prime concern, consider a self-inflating torso-length sleeping pad, which is made to pad from your shoulders to your hips. The 37-inch-long Pacific Outdoor Equipment Uber-Light (*Est. $60) weighs just nine ounces despite its one-inch thickness. However, a review of the Uber-Light at BackpackingLight.com notes that it's not warm enough to function well as a standalone sleeping pad, and the usable length is shorter than 37 inches. This sleeping pad is designed to supplement a longer pad for extra comfort.
Instead, BackpackingLight.com recommends the 10.4-ounce TorsoLite (*est. $70) by Bozeman Mountain Works. It's also an inch thick, and its width tapers along its 32-inch length to save weight. (At the upper thigh it's only 12 inches wide.) BackpackingLight.com puts this sleeping pad on its list of gear for three-season ultralight trips. Tests there find it tough and durable, and even women testers say it's comfortable down to 15 degrees. It packs to a compact 8 x 4-inch roll.
Some inflating sleeping pads use just air without foam and need manual inflation. Reviews say these camping air mattresses lack insulating power, though you can use a closed-cell sleeping pad on top to stay warmer. A 2004 comparison review at Backpacker Magazine says the Pacific Outdoor Equipment InsulMat X-Lite Compact, now the Ether Compact (*Est. $45), is cheap and light, but hard to inflate and only suitable for temperatures above 40 degrees Fahrenheit.
The Big Agnes Air Core REM Regular (*Est. $50) is similar, but a full rectangle rather than tapered. It does get some nods from reviewers, but we also found a lot of complaints about this model. The Backpacker review says it's so slick that it's easy to slip off. Also, one of the test pads blew a seam and even the repair kit couldn't fix it.