George Wright has had a fascinating renaissance with a low-key in-house restoration with work by Mark Mungeam. It may not be perfect, but it's the best it's now since maybe the decade it was built.
Triggs is a fun course with lots of potential, but I remember it being a rather small site.
The Orchards is also one that has improved over the years since it has become a regular US Womens Open site, but it's not perfect.
I played Wachusett not too long ago, and they need a sprucing...shouldn't be too bad, just needs some green expansions really to put some teeth back in.
In the Boston area, most private clubs have done work in the past decade or two. There may be some opportunities in Northern New England where courses have been neglected, as available money usually decreases as one gets further from Boston and NYC.
While driving with the kids up to Santa's Village in northern NH, I saw that Waumbek (billed as the oldest course in NH) had gone fallow, but then I was pleased to see a few days later that a new owner had bought it and was planning on keeping the course. Should be fun to see that one reborn, I've never played it.