I'd highly recommended to those who have very limited time in Taipei (1~2 days) to travel with MRT.
The MRT will takes you to the major highlights in Taipei. Eg: Shilin Night Market, Chiang Kai-Shek Memorial Hall, The 101 Taipei Building, Tamsui Fisherman's Wharf , & etc.
It's rather cheap to travel too. Minimum of 1 stop only cost NT20/-. (http://home.trtc.com.tw/EINFO/eticketprice.asp)
Make sure you vsit the official web site of Taipei Rapid Transit Corporation for detailed info.

