I've always used mono, namely Lazar and Rio Slickshooter. I always found Lazar better, but the slickshooter was cheap and accessible (seems like the Lazar is always out of stock).. I typically replace it every or every other year.
But just a few weeks ago, prior to a trip to the OP, i went to Pacific Fly Fishers to grab some new running line. They recommended Scientific Anglers absolute shooting line, Flat Mono. In his, words, it's better in "pretty much every way" as compared to the slickshooter that I was using. I gotta say he was 100% correct. I used the 42lb version (you'd probably want a little lighter), but that stuff was amazing and a huge step up from anything i've used prior. Hats off to PFF for the spot-on recommendation.
Is it translucent (like Amnesia) or opaque (like Lazar)? The 25lb might work, for my purposes.