Multimat
Superlite 25 Self Inflating Mat - Red and Black

Used this on the West Highland Way. Very lightweight, packs down small, easy to inflate. Takes a bit of squashing to get it to deflate again, but that wasn't really an issue. Comfortable, kept me fairly well insulated from cold ground and didn't slip about too much. The best thing tho was the lack of noise. My friends had more expensive, well known brand ones but they made annoying rustling noises every time one of them moved and it was very distracting. These multimats are great value for money.

For a mat one inch thick it is surprisingly comfortable and considerably better than a foam mat. I had attempted to purchase a Thermarest but after being let down by a supplier I tried the Multimat, at lower cost, and have not been disappointed so far, even as a side sleeper.

Excellent product especially considering the weight.