I've got Elixir nanoweb now, and they seem good although I haven't had them long enough to tell how they will compare to other types. You might get them cheaper on eBay (I did!)

I've used Martins (uncoated) and they lasted quite well for me - it might depend on what you play, how sweaty your fingers get, etc. I also used to use La Bella - are they still made? Haven't seen them for ages, but I haven't looked.