Well, I'm just like Harley in many ways so that's number 1. 2, She always makes me so happy because she is soooo fun & friendly (well, not to Batman but still!)
And 3.... she's CRAZY! There are more but it wouldn't fit. She rocks.
What i love about her is her devotion for the ones she loves(like red said xD),she's nice,adorable,awesome,crazy,beautiful,kind,genius, i also love her gymnastic skills!