Taipei Songshan Airport

It saves time because you don't have to buy tickets. I also bought an EasyCard (which can also be used on the MRT) to ride the bus, and it was a relief to be able to get on and off without worrying about the fare. I'm not sure if I used it enough to make it worthwhile, but it's probably a good idea for those who go to the furthest stations on the MRT and get on and off frequently. The first hurdle was figuring out where to pick it up, but I got it from a station attendant at a glass-enclosed, circular information counter-like place next to one of the ticket gates at Taipei Main Station. It was basically a matter of showing the voucher and saying "one day free pass, please."