There are many clues given during the course of the show as to [Stars Hollow]’s location in Connecticut, but unfortunately no one town fits all clues. Hartford is supposed to be within 30 minutes, New Haven is allegedly 22.8 miles (36.7 km) away and Woodbridge, Connecticut is 20 miles (32 km) away. Stars Hollow is mentioned not being in Litchfield county, negating all towns within. Towns mentioned as being close include Woodbury, Litchfield, Beacon Falls (generally in the central south west of the state), Groton, and New London (in the south east). However, towns in eastern Connecticut are unlikely as they are farther from Woodbridge and Hartford. The most likely town candidate would be Meriden as it is 22.8 miles (36.7 km) from New Haven, around 20 miles (32 km) away from Woodbridge, and only 30 minutes away from Hartford. This information can’t be reconciled any better.
This is a high quality wiki page! Not only do you have the above paragraph, in which the writer attempts to precisely locate a fictional town, but you get an exhaustive list of every establishment mentioned over the course of seven seasons of Gilmore Girls. (I will always have a great fondness for the often mentioned but never seen Al’s Pancake World.)