I'm looking to buy a new car and all of these have been recommended. I'm looking to buy a nice car but I want it to be good on gas. I don't know much about cars so I thought you guys could give me some idea of the pros and cons of each car?

I drive a Mercedes C class. Its a C220 with the diesel engine.
I find it super to drive, both around town and on the motorways, where it is very responsive.
The best thing is that I am regularly getting between 45 to 50 miles to the gallon.
I would recommend the Mercedes C220 to anyone.

The Maxima should be replaced by the TL as the G35 is already there.

Regardless, just buy the BMW 3 series...all pros and cons will lead back to the 3 series.