I’ve talked to girlfriends about this and its a few things:
1) Size of black cock (most of time)
2) Way they move their hips and bodies when they fuck
3) Smooth silky skin
4) Muscular bodies
5) Smell of black man
6) How much they love women– any women really but mainly white women (tall blondes like me are REALLY appreciated!)
7) Feeling safe and protected– amazing to see the fear and respect in white mens eyes when your with a confident black man– white men wont even look him in the eye, they usually look down when the black man looks at him
8) Feeling of being with a real man, no metrosexual, “getting in touch with my inner chd” shit– yuck. a black man is a proud confident man.
There are probably other things for other reasons but these are the most common ones among my girlfriends. 
