Just back from a nice trip to Plymouth, MA with our two children (6 & 4).  We stayed at the John Carver Inn which was a really great find for us.  The hotel features a fun pool complete with a water slide that runs through a replica of the Mayflower ship.  The kids had a ball.  Lifeguards were on duty and it kept them entertained enough to want to return both nights.  

The pool area also features a hot tub within a replica of Plymouth Rock (must be 16 to use), and a Sauna (must be 16 to use).  In addition, there is a nice full length balcony with chairs & tables to relax on with open french doors to the pool.  (Adult drinks are permitted but only with plastic containers).

Other amenities include a small workout room with two treadmills, and an elliptical machine that all face a bright flat screen TV.

The John Carver Inn is attached to a Hearth & Kettle restaurant for convenience, and the hotel issues discount vouchers for guests.  The hotel is also walking distance to the waterfront, including Mayflower II, Plymouth Rock, Jenny Grist Mill, and some cute shops and various restaurants.  (Woods Seafood, The Lobster Hut and The Weathervane for seafood, Ming Dynasty for Chinese, and Trullios for some great sicilian pizza.

Be sure to stop by the Plymouth Bay Winery for some free tastings of some interesting fruit wines.

Within just a few miles you will also find a number of family restaurants at Colony Place, ranging from Red Robin (great burgers!!), Bertuccis, Chilis, etc..  In that same plaza there is a 24 hour Wal Mart and a large strip mall full of stores.

The nice thing about Plymouth is that it is close to so many places.  We were able to drive to the Cape in less than an hour, and then up to Duxbury Beach in about 15 minutes.