You have the Mazda3 listed and I recently purchased one after doing months of research. My final two choices came down to either a Honda Civic or a Mazda3. This is because I wanted a commuter car that gets in the 30ish MPG.
I went with an '07 Mazda3 that had 86K miles. Purchase price was $6650, and I think that's a decent deal for what it's equipped with. 2.3L engine, leather seats, sunroof, heated seats, etc. I had to put another $800 into it because the previous owner didn't keep it in great shape.
Bottom line is I'm 19 years old and I wanted to get a car that's fun to drive. I can buy a more simple commuter car later in life when I'm older. The Mazda3 goes fast, if you're into that. I absolutely love my car. Did I spend a bit more than I would have on an old Honda Civic? Yes. But I made the right choice.