Westfield on the B&A would be worthwhile - it's a bit close to Springfield, but fairly large (41,000) and has Westfield State. Not suitable on the LSL, but a MA-centric intercity service should have it as a stop. On the B&M, you have Williamsburg and North Adams close to each other, plus the ex-Amtrak stops at Mechanicville and Watervliet (Troy), but that route is wayyy out of the way from the B&A. If it's ever decided that the B&M is worth passenger service - and honestly I think it could easily support a couple round trips - it'd be better to go the whole way to Boston so you can pick up Millers Falls, Orange, Athol, and Gardner. Not a fast service by any means, but Route 2 is a bear to drive especially in winter.