The best way to move around Bali is always by taxi. I do not recommend to rent a car, because the people over there usually they do not have car insurance so in case of accident, even when is not your fault can be a problem. So to avoid this, especially when you are on holidays, it´s easier to rent a taxi. And if you like the driver, offer him to stay with you the rest of the days and then you can negotiate a better price. I can recommend you MADE WARTA phone:081 338 510 814 friendly and serious
I forgot to say that Made Warta is the guy in the picture with blue shirt. He can also drive you to places for shopping and he knows the best beaches in Bali for surfing. Very nice guy and like his profesional card says "Clean Reliable Service"