Fruki is pretty good, roughly as good as Antártica imo (though I'd give Antártica a slight edge still). But it's only found in Southern Brazil, while Antártica is available nationwide, so the latter is much more popular.

The one regional soda I'd like to see become more popular is Mineirinho, which I've only ever seen sold in Rio de Janeiro (the state). It's such a peculiar/interesting taste, have not had it in years now.

Rio also has a regional guaraná called Guaravita, but it's not really a soda as it's not carbonated. It's more like a juice (and it's marketed as "natural guaraná"). It's pretty good too!

Damn, this conversation made me thirsty lol