Tokyo Monorail
The Tokyo Monorail that runs between Haneda Airport and Tokyo, with an average interval of only 4 minutes, can take you to Hamamatsucho Station in as little as 13 minutes, where a transfer to the JR Yamanote Line can be made.
It feels a lot like the MRT in Taiwan, but honestly, it's so much better! No worries about bad signal, and the views are beautiful.