Where do you think it's the best value to live in Boston which is T accessible?

I currently live near the West Natick T station, but I kinda feel like my life is somewhat dictated by the train schedule.

Living near a subway/trolley line would give more flexbility to my life and my finacees.

Any suggestions?

Basically we have only one car, and my job is on the North Shore (with parking). Her job is downtown, but can have issues because missing a train can cost her an hour or so.