If you want to give your credit card some exercise, head out to Kuala Lumpur Sentral in Kuala Lumpur Sentral. It's also full of great shops and restaurants, so you can spend the afternoon having a wander. Splash some more cash at NU Sentral and Kasturi Walk.
You can spend an afternoon studying the exhibits at National Planetarium in Kuala Lumpur. Amble around this vibrant area's picturesque gardens and enjoy its top-notch restaurants.