I always use semolina flour for pasta. Recently I've been ordering it from King Arthur, as the local coop stopped carrying it in bulk. Bob's Red Mill also makes a semolina flour and so does Hodgson Mill, though I haven't seen it on local shelves for a long time.
I've been tempted to order durum wheat berries and mill my own pasta flour, but haven't found a supplier yet. (25+ pounds of durum wheat would last me years.)
KAF is also where I get pastry flour, as the only stuff available locally is whole wheat pastry flour. Although GM unbleached makes a decent pie crust, I prefer a softer flour for most pastry.