Sanhe Night Market (三和夜市)
The residents of Sanchong District primarily come from the centre and south of Taiwan, therefore Sanhe Night Market is a good chance to explore a different style of night market when compared to others in Taipei. That being said, it isn't high on the list for tourists to visit when compared to others like Shilin or Raohe.
Sanhe Night Market is a nice break from the other seemingly over-commercialised night markets as it's built more for locals rather than tourists. The night market street is very long and narrow, with vendors running down the sides and direct centre for the entire length. It is very crowded.
The market runs the length of Zhongyang North Road (中央北路), and is exclusively pedestrian (with the exception of a random motorcycle here and there).
The primary Chinese dialect spoken around the night market is Taiwanese Hokkien, not Mandarin. Although all vendors will understand Mandarin (or sign language!), the atmosphere gives a small taste of central and southern Taiwan.
This night market is extremely long and narrow, with both ends conveniently located next to MRT stations.
Be sure to head over and check out the 'little brother' market, Wenhua North Street Night Market (文化北路夜市), located one block over to the west.