For me personally and what has worked for me is Tide Laundry detergent.
Tide Laundry Detergent is a bit more costly than some cheaper laundry detergent but Tide Laundry Detergent seems to work great for me when removing stains from clothes and other laundry.
Sometimes if the stain is really hard to get out you may have to let the laundry soak in the washing machine with the Tide laundry detergent for a few hours even all day while you're gone to work or out doing something else and then when you come back you can start the washing machine and the really stubborn stains should come out.
Although Tide is the best, Gain and Ultra Laundry Detergent also works pretty good at getting rid of stains on laundry