Here are some of my favorite Marlboro/Northboro spots and some that I have not tried:
Sullivans - odd location for sure, I lived and/or worked around Marlboro for many years but just found them recently...great 8 ounce burger and fries for $5.50 or so.
Another good burger at The Prospector on Lincoln - only lunch though and sporadic so call first.
Jake's on main street - GREAT breakfast menu, home made corned beef hash, service can be vexing but good food, good lunch menu too.
In the building in front of the Brazilizn diner, on main, there is Dino's ? Trattoria, only been for appetizers but it seemed promising.
Small Thai restauarnt on main, near Dino's....great Thai fried rice with basil, made with brown rice on reuqest.
Boar's Nest sandwich shop on main same ara, looks good but never been...could be a good Subway alternative.
Sergio's...Route 20 east...good breakfast menu, build your own omelette
Firefly's BBQ on route 20 E...awesome
Stephen Anthony ? restaurant on 20 E toward Sudbury, Wayside Inn area, great home made maple sausage.
Route 20 W across 495:
Good sit down chinese restaurant in the plaza where Hannafords and Panera are (forget the name)
Beezers in the summer for ice cream and good Chicago dogs
Britney's - SUPER breakfast with a huge menu, good quality, great home made hash browns
Further out there is the Steakloft, looks promising but never been there
Will be happy to provide more info on any of these