One I used to ask was do you have IS9002/BS5750, but that was 15 years ago and there are better questions to ask. A good question is also sometimes better than a good answear as it shows you understand things from another perspective and have the ability to ask questions instead of blindly accepting what you are told all the time if your unsure.
So what are your favorite questions and not how much TAX did the company pay type questions, the ones that give you lots of wonderous information and yet still puts them on there toes a bit as well if they are weak in some area's of managment/running the company of methodology. I asked what Q&A methodologies do you use in a interview once for a company called RIM; Was not a great answear. My question about IS9002/BS5750 was one which showed how well organised the company was at the job in hand and how well documented the role was. The answear tells you what kind of mess your getting into and also if you should be asking for more money (danger money if its somebodies spagbowl code/system :).
So what questions as a programmer do you ask the company in an interview, that is applying for your service. Anybody have one they care to share?