I'd love to see this for Taiwan. I'm here now (on my Nth trip where N >= 11), and my impression is that 7-11 is the clear winner in all the cities I've been to, followed by Family Mart and then some stragglers like Hilife and OK Mart (it's ok).
My personal favorite is probably Family Mart, because they have multiple very delicious vegan rice balls to choose from.
My personal favorite is probably Family Mart, because they have multiple very delicious vegan rice balls to choose from.