Which train stn is nearest/easiest to Wuzhen Water Town from Hangzhou Stn: Tongxiang or Jiaxing?

Tongxiang Train Station is the nearer one. After arriving, you can take a taxi or hiring a private car to get to Wuzhen Water Town. :-)
In addition, nowadays, most people like going to Wuzhen by taking direct long-distance bus at HZ Central Bus Station. The schedules are from 07:00 to 18:20 with the ticket fare of CNY 30 per person.