Dinner- Mass. State Line - Hartford off I-84
There's the restaurants at the Promenade Shops at Evergreen Walk in Manchester, CT. There is Bellini's which is a very good Italian place, there's Burton's grill for American fare and a Ted's Montana Grill for steak. All three are good at what they do. I have been to all 3 over the last couple of years and had good meals at all 3. They are not far from 84 just before you hit Hartford.
The other suggestion would be Max Amore or Max Fish in Glastonbury, CT. Both are in a small, upscale shopping area about 15 min from 84, a little East of Hartford. Great meals at both. Max Amore does very good Italian food. J. Gilberts is across from the Max's and has great steaks. I would put it on a scale with Ruth's Chris and Capitol Grille.
Outside of Rein's Deli, the area between Sturbridge and Manchester is a culinary wasteland.
Have a nice trip and hope you have a great meal wherever you choose to go.
Wait...you missed a few in Manchester! ;) Everyone talks about Pepe's Manchester outpost and forgets Mulberry Street on Main Street in Manchester--excellent, excellent pizza. And if it's pizza you want, try the Italian Job! I am overdue for a return trip.
But if I was staying overnight and wanted more of a special meal, I'll second J. Gilbert's in Glastonbury (their crab bisque is killer, too) and add Cavey's in Manchester. Wasn't the chef there recently nominated for a James Beard award? Wow, was that two years ago already?! In any case:
In West Hartford, Bricco is a great dinner option. If you'd prefer to be on the other side of the river, there's Bricco Trattoria in Glastonbury (haven't gone yet, it's on my list).
Rein's Deli is a popular spot. It's in Vernon, CT (Exit 65 off Interstate 84). I've only eaten at their West Springfield location, now closed, but the Vernon location certainly has a following.
If you're staying in or near Manchester, the possibilities increase, although much of Manchester is mall hell.