Hayley.
I used to love this spelling for the longest time, but in recent years I've always liked
Haley a bit better, pronounced hay-lee.
Images:
Hayley - hay, golden yellow, beach, sky, sun, woman with blond hair and blue eyes, athletic.
Haley - blue, grey, rain, sophisticated, woman with brown hair and grey, blue or green eyes, studious, calm.
Hailey - hail, social media, instagram, Bieber's wife, celebrities.
I find
Hailey to be much less classic and sophisticated than
Haley and
Hayley. Therefore I'd pick one of the other two.
Weirdly enough I don't mind
Kailey at all.