Rihana Run This Town for sure. She also has her own fashion and beauty brand with a similar style - https://www.buzzfeed.com/raziameer/celebrity-owned-brands-that-are-making-waves-in-th-3afp9x5bbg. Her songs motivate and inspire me.
When I am in a dark mood, I dress myself as if I am going for a party or lunch and that makes me very confident and happy.