Dennis - we like 7/16"
New England Ropes Sta-Set (not Sta-Set X). It's good on the hands, doesn't twist or hockle, and is low stretch. You can use the smaller 3/8" too, but the 7/16" is easier for the someone tailing to hold on to. It's also very reasonably priced when compared to some of the high tech lines. I've found good deals online and at Hall Spars sales.