If you are going to Taipei city, I recommend limousine bus.
Because you don’t need to walk far at Taouan Airport and Taipei Main Station as well as it’s cheaper than trains.
I will show you how to get to the bus terminal in Taoyuan Airport 1 and Taipei Main Station.
Bus terminal in Taoyuan Airport 1
When you get to the Arrival hall, turn right there.
You will see an exchange booth, a telecommunication counter and restrooms on your right side. I think you should exchange your money first because you will need it for your bus fare and food. And go to the restroom, because there were no restrooms in the bus I took.
Also you can buy the Prepaid SIM card here.
The telecommunication counter is open from 7am to 12am only.
Head a little farther on, there is a large information board.
Go down the escalator back of this information board. You will see the convenience store “Hi-Life” on your left side.
Turn right here, soon turn left to get to the ticket counter.
The bus to Taipei I recommend is “KUO-KUANG MOTOR TRANSPORT“.
You can buy the ticket at counter 7 or 8. One way ticket is 140TWD. But if you buy round trip ticket, the price is 260TWD, that’s about ＄10 USD.
The bus will leave the 5th bus stop outside the building.
Leave your luggage and show your ticket to the staff here.
To Taipei Station
You can have a seat anywhere you like, it’s an unreserved seat.
The AC in the bus was a little strong, so you might feel cold. I needed a long-sleeve shirt.
You can charge your mobile phone in the bus.
I think you will get to Taipei bus terminal in about 60 minutes.
The place is in front of Taipei Main Station near KUO-KUANG BUS TAIPEI TERMINAL. You can take a train to your final destination soon. Also you can take a taxi.
The bus returning from there will leave in front of the bus terminal.
It’s open for 24 hours a day.
For your information,
when you show the ticket from the airport, you can take the bus going to Ximending for free. The bus is available from 11:30am to 6:30pm only.
Have a nice trip!