For just about every razor, Astra sp is my blade of choice. The only exception is that I use Feathers in my Feather AS-D2 - they seem to have been made for each other.
Feather, Astra SP, Polsilver SI.
These are all smooth and great for my beard for about three shaves. I haven't found a blade yet that will go more than three shaves without pulling, and making weepers a plenty.
So far, though I can't say I've tried a broad variety, it's Polsilver SI. I'm also impressed with this blade's longevity. More expensive nominally, but per-shave cost averages out well.