I visit Taipei a few times a year. There are 3 things I must eat when I’m there. Not just once, but multiple times! The good thing is that all 3 are found in one place – Xi Men Ding.
First on my list is “Xiang Xiang Ji” or Ji Guang Delicious Fried Chicken. They have many outlets in Taipei, from streets stalls to stalls in malls. You can’t miss it when you exit from the Xi Men Ding MRT station. It is in a corner, just at the start of this famous street. It’s best eaten fresh when it is hot and crispy. And I always ask for it to be extra spicy (“jia la” or “da la”).
Its flavorful seasoning is so good, I even like it when it’s cold. I usually leave a packet of these bite-size chicken in the hotel room for a supper snack! But be warned, your entire room will be filled with its powerful smell. Not a bad thing for me. But for those who want to enter their hotel room, feeling like you’ve entered a Banyan Tree Spa… then this is not for you.
With a packet of chicken in my hand, I will eat and walk towards my next destination – the very very popular Ay Chung Mian Sian (Flour-rice Noodles). I had this 20 years ago when I visited Taipei for the first time at the exact same location. Nostalgic.
There are only a few small portable tables and seats in front of the shop. Most customers buy and stand around to eat, slurping and perspiring and totally enjoying that little potent bowl of noodles, that comes with little bits of chewy intestines, and a broth that has the perfect balance of stickiness and smoothness. NT 6o for a large bowl and NT45 for a small.
Once I’m done with the noodles, I need to wash it down with a nice White Bitter Melon juice and maybe a Mango Shaved Ice dessert. Just 5 minutes walk, and I’m at my regular haunt – Three Brothers & Sisters (三兄妹).
I apologise that I don’t have the address to these 3 outlets. But you will definitely see them when you are in Xi Men Ding. If not, ask a local… they will know and they are usually extremely friendly.
Ximending
Sec. 1, Zhonghua Rd., Zhongzheng District, Taipei City
eatmekevin 
My must have at Ximen is also Xiang Xiang, esp when it is piping hot!
Ah yes, best when it is piping hot! Try the fried squid when you are next there… it is lovely too.