With old style apples making a major comeback, and apple breeders developing new fruit for its flavor, not just its looks and shipping capabilities, I think this brief guide may be helpful when you are faced with fruit you've not tested out in the pot or oven.
Firm Apples for Pie:
Chestnut Crab (a personal favorite), Connell Red, Fireside, Granny Smith (the great stalwart tart cooking apple), Haralson (another trusty tart pie apple), Keepsake, Liberty, Northern and Prairie Spy (two additional tart stalwarts), Regent, and Rhode Island Greening (another old time tart gem).
Chunky Apples for Pie, Sauce and Baking Whole:
Baldwin, Cortland, Fuji, Green Pippin, Honeycrisp (exceptional flavor and texture), Hubbardston Nonesuch, Ida Red, Ozark Gold, Paula Red, Reine des Reinette (extraordinary flavor), Roxbury Russet, State Fair, and Zestar.
Tender Apples for Sauce and Baking Whole:
Beacon, Jonathan, King David, MacIntosh, Macoun, Mutsu, Red Baron, Wealthy, and Winesap.