Best factory stereos between these cars?

Hello-I apologize if something similar has already been posted, although I didn't see anything when I searched.
I am starting to research buying a new car, although it might be a year or so before I actually buy. I was hoping to get a hybrid, and was narrowing the choices to Nissan Altima, Ford Fusion, Hyundai Sonata, and Chevrolet Malibu (would have to wait until the 2013 model for a hybrid on that one).
Obviously, a stereo is not my only concern when buying a car, but evaluating a factory stereo is difficult (at least for me) when just looking at the specifications. Right now, I have a 2006 Chevy Malibu, and the factory stereo is not that good, which is something that I am reminded of everytime I drive my wife's Honda Civic.
Which of those cars have a good (or bad) factory stereo? Anything else I should know about those models?

most factory stereos are marginal at best. The real thing to look for is the features you want.

Thanks-I'm no audiophile, but I'm just looking for something acceptable. I can't even listen to some cd's on my current stereo because it is so weak. But it seems like the factory upgrades always require you to spend $2,000 to get all these things that I don't want. Maybe I should just upgrade it elsewhere after buying.

I typically start over in the audio dept, but my latest car is a 2001 - I may not be able to do that when I eventually have to buy a new car.