My girlfriend rarely compliments me. What do I do?

You have to be careful with how you approach this when you talk to her about it, but yes, definitely talk to her about it because she may have no idea she isnt doing that enough for you. Simply bringing it to her attention will help because she will be aware this is something you need from her. So I would say something to her like, "Hey if Im wearing something you like or look good one day I would really appreciate you telling me that so that I know its what you like. It makes me feel good when you compliment me, I love hearing you say X Y and Z." Whenever she actually does it on her own, you need to thank her for it and reinforce that behavior like as if you would teach an animal.

Im saying this from experience because a guy I dated said he felt like I never appreciated where he would take me. I thought I was making it clear that I loved where he was taking me because I was commenting on everything and smiling and enjoying being there but he needed to hear me say "I appreciate you taking me here" directly. I had no idea.

Find a new GF, if after all this time, she should be able to say something nice. She has a mental illness if she cannot even say anything nice or even, I love you.  Move on,

Listen to her heart beats to understand the Magic. Play the music to make her happy. Her smile would be a compliment to you.

Discuss it with her. 

She has to learn everything isn't about her and acknowledge others. It's not going to work out if u have to constantly remind her to compliment you