Hi there!
I'm an admitted GM fan, but I like all brands that offer something I want. Unfortunately that's a thin list these days

At least there's fun stuff on the used market.
A friend has a 350Z, and it's a nice car. Seems quick riding shotgun. There is a 370Z in the parking lot, same color as his. I like the looks of both cars. His only recurring problem has been the auto up/down window system. Several dealers have tried to fix it, all unsuccessful. It's minor so he lives with it.
I've driven two NA Miatas, and sat in a NB, and they're okay but I don't fit as I'm too tall and my legs hit the steering wheel. I don't know if I fit in a NC but I don't like the looks.
I don't know about how I fit the S2000 but it looks nice from the outside.
So, the Solstice gets the nod -- I like the car, and I'm a GM fan, and I fit. If I had fit in a NB Miata, I probably would have bought one back in '03 when they were deeply discounted.