I've been driving my '03 Malibu LS (fully loaded) for about a year now. I purchased it used with only 26,000km on it!
I really like the way the car rides. It's so quiet, even on the highway, and it soaks up bumps really well. The interior fit ad finish is ok, but nothing amazing. It's got nice pickup in the city, and really good passing power on the highway (I've passed with ease at 150 km/h on a steep hill. The worst drawback for me are fuel economy. I only get about 16 city and 22 hwy carefully, watching my driving habits, 15 & 19 driving normally. The other thing is that it feels cheap at times (ie some of the buttons/knobs). It's not too bad, but should be thought of as 'just a car'.