The 1st is Mercer County Bark Park it is located at 334 South Post Road, West Windsor (directions) and has two dog park areas, one each for large and small dogs.  This is a public park so shot records are not required and there is no admission fee.  The park is open 7  days a week, 365 days a year, dawn to dusk.  I have been a few times with my dogs and have had a positive experience.

The other local dog park I am aware of is the Rocky Top Dog Park located at State Hwy 27 (a.k.a. Lincoln Hwy) Princeton, NJ 08540 .   It is a bit of a drive, around 20mins but well worth it.  This park is a private park.  It is only open to the public on weekends from 12-4pm.  If you are going for the 1st time bring your shot records, they will not let you in without them.  The cost is $10 for the 1st dog, $5 for the 2nd.

Every time I have visited the park with my two dogs there have always been plenty of friendly dogs to play with.  They have over 3 acres for the dogs to enjoy.   The park is great in the spring and summer if your dogs enjoy the water.

If you are aware of any other dog parks please share.  Thanks.