What everyone should try at least once in a liftime is Taiwanese food. It's completely different from what I'm used to eat in Europe but really delicious!
Since I arrived in Taiwan, I've already tried what seems to me like hundreds kinds of food and I still find new ones to taste! Rice, pasta, vegetables, tofu and pork are the most popular ingredients and Taiwanese can serve them in so many different ways!
If you don't like rice or pasta - don't worry, you will find something else to eat, e.g. ...
Taiwanese dumplings served in many different ways: with pork or with curry, spicy or delicate ones.