Gaga is the only one who actually tries. Her video choreo is always really good because she doesn't have to sing live while doing it, and her live choreo is hit and miss at times.
Credited to her heritage, but Rih does have a natural sense of rhythm that GaGa lacks. I do love (some of) GaGa's choreographed routines but I prefer Rih's natural swag/dance and her choreographed dances. Still love the WFL choreo so much.
From what I've seen from Rihanna, though, she seems to have some natural rhythm. She could probably slay if she tried, but she'd probably have to lip sync while dancing since she's horrible at controlling her breathing.
Gaga. It does not come naturally & she needs a better choreographer but her dancing in her videos is pretty decent. Rih is probably along with Nicki the only black girls I know who can't dance to save their lives. Katy dances like a suburban white girl, that's all I'll say.