Goofs

In the Pilot episode Luke's diner is in the middle of the block and doesn't have a "William's Hardware" sign. The letters are instead engraved above the door.

When Lorelai and Rory are at Luke's during the first scene, Lorelai introduces Rory to the man passing through on his way to Hartford. She tells the man that Rory is sixteen. Later in the season when Rory has her birthday party, she doesn't age to seventeen. She stays sixteen.

However, since her Rory's birthday is coming up, she could just be rounding her age up to 16.

After Dean helps Rory carry her box of books, we see a view of Luke's diner from the outside; Lorelai is in a black shirt and ponytail and Rory is in a Periwinkle shirt, both of them enjoying a conversation. In the next shot, we see Lorelai in a purple shirt with her hair down and Rory in a brown or black sweater with a red turtleneck, both silently eating. The first shot of the outside of the diner was actually from the last scene when Lorelai and Rory went to Luke's after having Friday night dinner at the Gilmores'.

In the opening scene, and all episode, Luke's diner is considerably smaller than the rest of the series and a bit different. Also, the "Good" and "Food" signs are on windows which don't appear to be part of the diner space (they are to the sides of the diner's walls when looking from the inside).

The Gilmore Mansion is different than in later episodes. The entrance way has steps to go up to the front door landing. In future episodes, the front entrance and driving area are very different. No steps to the front door and the parking area in front keeps changing, adding bushes and a fountain type sculpture.

When the girls first meet Mrs. Kim, she offers them muffins with "no dairy, no sugar, no wheat", yet when she leaves to take care of a customer she says the muffins are made with "sprouted wheat". Sprouted wheat is still wheat.

Kirk introduces himself as "Mick" in the first episode. From episode 3 and throughout the series his name is "Kirk".

Lane and Rory talk about Lane's parents, yet in later episodes it is clear that Lane only has her mother.