I was born in Singapore and is still living in Singapore. Chinese is one of the major languages and I use it on a day-to-day basis (more spoken than written).
I have been to China on many occasions, usually to visit my extended family in Xiamen. I try to visit once every two years and I usually stay for two weeks at one go.
I have been to Taiwan once, but not mainland Taiwan, rather just a small island named Kinmen. I traveled there by taking a ferry from Jinjiang (a Chinese county). I only stayed there for two days but it was sufficient to explore most of the island.
Other countries where Chinese is a common mode of communication and where I have been to include Malaysia and Indonesia.