I've used all sorts of mats in all sorts of places. Are you wanting to go ultra/ultra light or is comfort more your thang!
I've mainly settled on Thermarest mats, generally from their ultralight range though have stayed away from the three quater length ones as I like to keep my down sleeping bag off of the ground. I tried out their Neoair ones but found that they rustled like a crisp packet and disturbed my sleep.
You could also click on the banner at the top of the page (Alpkit) they do some stonking gear. Not used their mats personally but they get good reviews from folk.
Another option though not cheap are the Exped downfilled mats. Pretty hefty price tag but the toastiest mat I've ever slept on. Really was a ***** hotel experience, but with a ***** hotel price tag. Depends on how much comfort you need while away, I'll happily sleep on a lumpy ploughed field but getting a good nights sleep is important, especially if pushing yourself during the day. Also you're likely to loose more heat into the ground through conduction than through radiated heat through your sleep bag, so a descent mat is a must.
Sent via smoke-signal from a woodland in Scotland.