Yoruichi Shihouin
Yoruichi Shihouin is definitely one of the best anime cat girls. She is the former captain of the Gotei 13's 2nd Division and the previous leader of the Onmitsukid. Marenoshin Omaeda was her Lieutenant. She has given up command of both posts and now works with Kisuke Urahara and Tessai Tsukabishi in the Urahara Shop in the Human World.
Yoruichi can entirely turn into a cat. She is a joy to be around and enjoys teasing her friends. Don't be fooled into thinking she's simple to deal with; she's a real badass who specializes in martial arts and hand-to-hand combat. Yoruichi's battles are always entertaining to witness. Yoruichi is bright and humorous, with deep knowledge of Soul Society and its workings as the previous head of the Onmitsukido and captain of the Second Division.
If you hear her speaking in her cat form, you could think she's a man because she has a manly voice. That's why she's frequently misidentified as a male cat. However, when she first transformed into a girl, she managed to terrify the hell out of Ichigo. She was also brave enough to appear naked in front of him. In short, seeing Yoruichi Shihouin on TV is always entertaining.
Anime: Bleach