The best line is the Warpspeed. If you need the comfort zone 3/8" is the best, otherwise the 5/16" runs a bit better. The nice part about Warpspeed is that you can strip the cover off the part that runs through the blocks so it really does a great job, yet keep the cover on the part that is in your hands.
Warpspeed's core is the strongest, least stretch on the market and is already UV protected and they have color coded lines.
You can go to our Catsailor Online Marine Store by clicking on the following link: http://store.catsailor.com/tek9.asp?pg=products or to go directly to Warpspeed, click on the following:
http://store.catsailor.com/tek9.asp?pg=products&specific=jscpemirm
The price of the 5/16 is $1.73
and the 3/8 is $2.34

Good luck and good sailing,
Rick