I use Mr.Clean with Febreze mixed with bleach. It gets all of the stain off, and does not discolor most surfaces. Also, you get a nice fresh smell that last for about 1 to 2 weeks.
Bleach is the best way to remove mildew stains on hard surfaces because it kills the mildew's roots. Dilute 10% bleach 90%water and scrub the stain thoroughly.