She only likes me when i have food

Have you thought of trying out some sports with her for fun?  I know that I've formed a much tighter bond with my girls this way.  Perhaps more one on one time with her?  Take her to places and take some classes.
Also, do you feed her?  If not, take that over.  Try clicker training as well if you haven't already.  It has also really strengthened my bond with my girls.  Maybe even start carrying treats in your pockets without her noticing and whenever she comes up to you, give her a treat.  Make everything you do with her a bunch of fun.

What's the like with your other dogs?

Lucy is currently taking flyball classes once a week.  She is learning the sport but gets distracted and only comes back to me when I have food.  She is great with my other dogs.  They all play with each other and sleep and cuddle together. 

You know some dogs are just more independent than others.  They are all different.  My girl Sprite is that way, really doen't want to be petted that much by me doesn't cuddle or anything like that.  My boy Timmy on the other hand is the complete opposite.  I will tell you though that Sprite is the most devoted dog to me that I have ever seen.  She always has to know where I am and stay close to keep an eye on me.  It's great that you are doing flyball with her and may I suggest that you also try some other training with her like obedience or agility.  With your dog being food motivated it should be easier to learn,  In these sports especially obedience you are working with the dog and they have to take all cues from you and be right there along with you.  That helps build the bond.  Flyball is more of a independent type of sport where you send the dog off to do there thing and come back.  Before anyone flames me about Flyball, I think that is is great and I've seen the dogs and they look like they are having great fun but it is a different type of work than other dog sports. 
Just remember that all dogs are different.
 
Let me add that it can be more difficult in a multi-dog household for one to bond.  That is where the 1 on 1 training can really help.