This very plush guesthouse has big, white, comfy dorm beds, and the shiny shared bathroom facilities are spotless. There's a coffee lounge and laundry, and a simple breakfast is included in the price. There are beds for about 100 guests spread over a number of floors.
NK also has ensuite private rooms with some great views of the river or Taipei 101. However, they are quite pricey (around NT$2700 a night) considering there are none of the typical hotel facilities such as a restaurant or gym.