Lau Deng Dan Dan Mian
I love this place, mainly for its red oil wontons, which have exactly the right mix of peppery spices with none of that nasty sweetness that simply ruins it for others. Their wontons are nice and small too, with a good quality filling - so much that I tried their "white oil wontons" today, to find them very tasty as well.
Of course, their namesake dan dan mian is great too. It's based on a peanut sauce (is that more of a Taiwanese thing than a mainland thing?), which fortunately is still good and spicy. The hot and sour noodles are another favorite (although the preference on that one still goes to Hometown back in Singapore, who has a stronger flavor). It's nice to get some "small plate" cold appetizers too, like the shredded tofu and cucumbers, which I can drizzle chili oil onto for an added kick.
This place is also known for their fen jin pai goo (steamed pork with glutinous rice), which I generally like, but I usually don't order here since I sometimes get little bits of broken bone in it. I also prefer a more peppery taste instead of chili. This place (02-2341-1260) is located across from Yong Kang Street (north of Hsin Yi Road, across from the original Din Tai Fung).
My usual routine is to finish up here, and then head down to Yong Kang Street for some mango ice at Ice Monster. Unfortunately, it looks like mango is out of season in Taiwan now, so I had to resort to a smaller mango-based sorbet, to my disappointment.