I like this place called AeroBile located near Taipei Main Train station that has travel SIM cards for almost anywhere in the world. Info in this thread.
Found this shop where you can purchase phone SIM cards before departing for USA and it will be ready to use when you land. They are an authorized distributor for T-Mobile which is one of the largest phone service providers in USA. Prices are quite reasonable.
An example basic plan: NT$1300 per month unlimited data plus 100 minutes talk.
Name of shop is “Tphone” located at No. 225-1, Section 3, Zhongxiao E Rd, Da’an District, Taipei City, Taiwan 106, tphoneusa.com .
Note: SIM card takes 3 d…