There are literally millions but you could try; babe, babes, baboo, baby cakes, cutie pie, cuddles, doll, doll face, fruit cake, or funny hunny. If you are looking to be even more romantic, then try something in Spanish like; ari?o, mi coraz?n, mi amor, mi vida, or mami. Check out more on this from http://openarticlesubmission.com/cute-names-to-call-your-girlfriend/.
In all honesty therer are tone ^ im a girl and i hav gotten barbie blondie shortie cutie sweetie ...... it goes on forever but olny once was i called dollface and honestly the guy that said it know sticks out like a sore thumb in my mind i thought it was sooo cute not sure why haha i did thoe :)
I always pick a "pet name" based on her temperament ... but from Elven. Geeky/Nerdy, I know. But it sounds romantic, and there's very little chance of anyone else having that nickname. My last gf I called "tiefling" ... in reference to the D&D race ... because that fit her personality. We're still friends, and I still call her that. LOL
How about babygirl my girlfriend loves it when I call her babygirl when I call her that she wraps her arms around me and kisses me what makes it even better is she is short and normally I lean down for her but when I say babygirl she stands on tippy toes (:
call her things that are unique, random and rarely used if you want to stick out and not be categorized with her ex's, like angel dove, angel eyes, boo boo kitten, panda paws, cuddle bug, strawberry dumpling, sleeping beauty, pudding head, chick pea, princess and pumpkin. I used all of these on many different gf's and they work really well if you know what i mean :)