The Prius is the world's best hybrid, and I personally believe the Prius 4 is the best of them all. A MINIMUM of 50 MPG is to be expected, and if you use the electric drive enough driving through the city (anything under 21 MPH), you'll easily be able to stretch that to upwards of 90+ MPG. There's no need to worry about plugging anything in with this Prius 4 hybrid--the braking actually charges the battery, so you'll never run out of juice. The transmission automatically switches to gasoline at the proper times, so it's a very seamless experience.
The Prius is roomy, we always keep ours clean, and it's incredibly reliable. There's truly no better car to rent!