You may get differing opinions on this, but I'd stick with a Methylene Chloride stripper. "Circa 1850" made by Swing is a great one, so is "Dads" and "Rock Miracle". Any good paint store should be able to supply you with a good stripper.
A word of caution; Methylene Chloride is carcenogenic. Use this stuff only where you have sufficient ventilation and wear the proper protection.