How about a nice drive through the woods with a stop for lunch?
To this end, let me propose a route. 121 is a terrific road that winds its way through Auburn, Chester, and Sandown, NH, and has lots of varying terrain with the occasional opportunity to carry some speed. It is a beautiful road with lots of country scenery. If we did it east to west, there's a great little place called Holidays at the junction of 121 and 101. If we did it west to east, there's a LongHorn Steakhouse on the Plaistow / Haverhill line.
For a western option, a lap around the Quabbin Reservoir is a good time. 32A to 122 and down the west side on 202.