I've been to Taiwan, Hong Kong, China, Japan, and South Korea. I love Taiwan because I have family there, who take us around and really let us immerse ourselves in their lives. I also love night markets there. Hong Kong was nice, a lot of people spoke English. China was nice, but not as memorable or enjoyable. However, that's just my own experience and shouldn't sway anyone else from going (oh, but you'll need a Visa I think). Japan was fun, we stayed in Tokyo which is a big city all lit up at night, and we visited temples. Language was an issue there, but luckily Mandarin and Japanese share a few noun characters in written word, so my Aunt would sometimes write down where we were looking for haha. As for South Korea, I was only there for about a day, so not very memorable for me personally, even though it was cool just because I used to be into Kpop. I have friends who studied abroad there and really enjoyed it though.