I got the Droid Mini. Been great so far. Awesome battery life. I like the size of it, it's bigger than my iPhone 4 (I think it's bigger than the 5 also), but not too big. About as big as I'd go probably. Can't stand having a big phone, and I'm not a small guy either.
The S3 shuts down and will not start up again. In the first six months, my partner had the motherboard of her S3 replaced twice due to sudden death.
I haven't had any major problems with my S3 but I doubt I will be sticking with Samsung in the future.
As for Android the best I can say at the moment is 'it's okay', it depends on how it is dressed up and who is dressing it up.
My faith in Google living up to 'Don't be evil' keeps getting knocked, I'm on a bit of a downer with Google at the moment.