The Mazda, without question.
And I say that after a thoroughly miserable three years owning a Fiat 500 that my wife just had to have. The thing's been to the shop as often as my brother's Audi, which I didn't even think was possible.
When the check engine light decided to come on (again) a few months back, and I set up a service appointment, I was chewed out by the service tech for dropping it off the afternoon before (I had a business trip scheduled). "Why are you bringing it here now? We don't have any place to put it! Your appointment is tomorrow, so again, why are you here now?"
I was seething.
"I'm sorry that this F***ing car breaking down again is such an inconvenience for you."
So if you're in the Seattle area and just have to have a Fiat, avoid Rairdon Fiat of Kirkland like the plague. Shady sales experience, and it only got worse from there. Car Pros in Renton is selling them now, and that's where I went for yet another warranty claim last month. They're much, much better to deal with, and that's where I'll go up until I trade this thing on a new Miata next month. Can't wait!