My advice.
- She's really not that funny, down to earth, cool, or talented. She is probably not even that hot. When someone is unattainable to you, your imagination and fantasies get carried away and fill in the blanks in such a way that a woman seems far more perfect than anyone, let alone her, could possibly actually be.
- What are you getting out of this "friendship", and what is she? You get to keep the suspension of disbelief alive for your romantic fixation, and she gets attention, validation, and the thrilling drama of watching you fawn over her and repeatedly turning you down. No combination of words or actions exists that is going to stop her from stringing you along and to become involved with you sexually or romantically. Have a few drinks alone and take a long hard look at why it is you value her as a "friend" so much.
- Tell her you have feelings for her that you cannot undo but that you realize it would not work out, and that keeping her around as a friend would be unhealthy for you. Cut ties, move on.