Mazda 3...of course I'm biased, as I own a 2005 Mazda 3 5-door, but after looking at a number of cars, for me it was down to the tC and the 3, just like you. I thought both were nice cars, but I went with the 3 for three reasons. The first was that although they were rated the same in terms of performance, I wasn't all that impressed with the tC, the Mazda 3 seemed to drive more "fun" for some reason. I also didn't like the interior on the tC at all. Seemed rather cheap, and the roof was WAAAAY too low. I'm only 5'9", I should not be almost scraping the roof like that. The third reason, and perhaps not a factor for some people, was that I wanted to get a hatchback so I could carry stuff if I had to. My Mazda 3 is fine unless it's something really huge, the tC is pretty worthless in terms of cargo space.