About 3 years ago I asked my best friend out... She said no... It didn't get awkward between us and now we are best mates again, I still like her and I have tried to move on but she is the only person I can think about. I am such close friends with her that she tells me everything about everything, even guys that she likes... Which kills me... So I play along and try and help her out because I know that she doesn't like me... Well I assume that... So what do I do?

Tell her again, if she feels the same way, back away for a while until the feelings die and pick up the friendship again, and even if you do, make sure you tell her that since you have feelings for her that you will be actively working to overcome, to have the decency to not tell you about her romantic life.

People want what they can't have. Unfortunately there is truth in that saying. Don't be a doormat. Make yourself unavailable let her wonder where her best friend is you should date girls as well. Not play games but you need to date also. Then she'll start to see what she's been missing out on.

I agree with mmresd.

Ask her out again. See whether things have changed or not. Explain to her your predicament, and stay away from her till you have sorted out your feelings.

Friends are nice but you still have to have a life without them so you can do your own thing, and explore, and experiment.