You may want the ultimate in lightweight materials or an insulated pad.
I have found the Big Agnes Dual Core, $90-$144, to be the best for me because I sleep on cold ground through cold nights. I discovered that a 2.5-inch pad allowed me to sleep far better than a 1.5-inch pad.
Your pad decision can be narrowed quickly by considering your type of travel.
•Minimalists and long-distance hikers: If you seek the lightest possible pad, pick a basic foam pad or a "short" or "3/4 length" of a self-inflating or air-pad model. Low weight and a small packed size override all other concerns.
•Backpackers: If you prefer a bit more comfort, compare pads with greater thicknesses and durability. The tradeoff, of course, is a moderate increase in weight.
•Family campers, boat campers, car campers: For you, size and weight are not limiting factors. You are free to choose a thicker, larger mattress for more luxurious sleeping comfort.
•Winter campers: Camping on snow requires more insulation. REI recommends the use of 2 pads: a self-inflating or air pad atop a closed-air-cell foam pad. The foam pad adds insulation and offers insurance in case the inflatable pad is punctured.