My brother lives near Copake, between the town of Hudson and the Massachusetts border, and we try to do a Brothers Road Trip each year and check out some cool spots either out there or here on the West Coast. This thread has some good suggestions so far...the closeness of Lime Rock is a big one, for sure!
If you get a long weekend or want to go slightly further afield, there are some great areas for exploring and doing guy stuff in the area. Among the top for me are the Finger Lakes region, Cooperstown, and Saratoga Springs.
We did a nice little trip west from his place (just past Ithaca) to take in Watkins Glen, some awesome waterfalls and lakes, the Corning Glass Museum in Corning, and the Curtiss Museum in Hammondsport (packed with history, aviation and motorcycle stuff!)
One year we did a nice long weekend in Cooperstown, also a bit west, complete with the Baseball Hall of Fame, the Farmer's Museum, Fenimore Museum, Omegang Brewery Tour, and some water-powered Cidery (maybe Fly Creek?) There are lots of small museums and historic sites in the area (for a small town) if you are into history.
Saratoga Springs (a bit North) is a fun area to poke around if you are a history buff, particularly if you like the colonial/revolutionary war period. We went there and took in the Saratoga battlefield, the Schuyler House, and a there is even a decent little Automotive Museum there. There is also some horse racing stuff, but we didn't go to any of it. There used to be both a company making Lotus Seven-esque replicas, and an awesome American-made high-end racing bicycle manufacturer in the area, but sadly those have both closed.
I've never been, but I hear rumors of ice racing in the winter if you stick around that long!