Fast, comfortable, and decent gas mileage. The GS 400 is a great car when you compare it to anything else in its class. Especially when it comes to reliability and quality. My previous car was a Benz E-320, and the Lexus blows it away in every category.
Power tilt/telescoping steering wheel that moves when you get in and out of the car. Comfy seats, 5sp auto, monster accellaration, great stereo, looks.
New headlights lens covers that don't get all cloudy after a few years.