I've had tremendous luck with AeroKroil and PB Blaster.
But a better "burner of a topic" would be: What is your favorite method for removing those VERY stuck nuts or bolts
1) Apply a good wack with a brass/copper hammer or ball peen hammer and punch. That breaks some of the corrosion up and helps the penetrator liquid to seep in. Soak with favorite goop. Apply a sharp turn with the tool. Don't go slow. My experience is that it will break off or strip out. If no luck..
2) Heat and soak. repeat above. if no go...
3) Nothing beats a very square end of a punch and a ball peen hammer. Set on the turning edge and knock it hard. The shock and application of torque often works.
4) Don't wait to break off the head before you decide to drill it out. If you do drill it out, use counter twist drill bits. Often the heat and vibration will screw it right out.
These are expressly the thoughts an experiences of a shadetree mech. I would really enjoy reading the thoughts of the pros that troll this board.