There is not much left to say about the Twilight franchise. Almost everybody knows it, whether one likes it or not. For people you actually enjoy the story of Edward Cullen and Bella Swan, Lionsgate released a set containing the first 3 installments of the franchise including new Exteded Versions.

The Extended Version of Twilight contains approx. 4.5 minutes of new scenes. But then again, the new scenes are also available as deleted scenes on the previously released Blu-ray and DVD. I am talking a few added plot scenes here which are nice to have in the actual movie but that is it. Those scenes increase or decrease the movie quality.

Compared are the Theatrical Version and the Extended Edition, both released by Summit/Lionsgate.

There are 11 differences:
6 additional scenes/shots in the Extended Edition
3 additional scenes/shots in the Kinofassung
2 scenes with alternate/additional footage

The Extended Edition is 262.54 seconds (~ 4:23 minutes) longer than the Theatrical Version.

12:01 Minutes
Bella comes down the stairs, she passes Edward and siblings, and goes to their car. Edward still does not feel comfortable in her presence but he can't take his eyes off her. Bella drives off.
41.42 sec

13:33 Minutes / 12:51 Minutes
The shot of Bella putting ketchup on her plate is different. The Extended Version is longer though. Bella asks her dad if he ate at the dinner every evening and says she could cook him a meal as well. Charlie then would like to know how it was in school and if Bella had made friends already. She explains she had met a few people and asks about Culles. He answers and tells his daughter some things about the family.
89.55 sec / 5.21 sec

Extended Edition	Theatrical Version

56:14 Minutes
The tracking shot of the branches is longer in the Theatrical Version.
1.25 sec

58:20 Minutes / 56:15 Minutes
The Theatrical Version contains a tracking shot to Edward and Bella sitting in the meadow. In the Extended Version, they are walking across the meadow until they kneel down.
Edward: "If I ever hurt you I couldn't live with myself. You don't know how it's tortured me."
Bella: "Edward. I'd rather die than stay away from you."
40.20 sec / 7.84 sec

Extended Edition	Theatrical Version

1:09:53 Minutes
Carlisle and Esme talk about Bella and Edward. Then she pushes him against the wall and they kiss.
23.77 sec

1:07:16 Minutes
The Theatrical Version also shows Bella coming up the stairs.
0.7 sec

1:10:33 Minutes
Bella asks Edward if he knew how cool it all was. Then she discovers his diaries. But he tells her not read them unless she had trouble falling asleep.
30.95 sec

1:07:33 Minutes
Theatrical Version: Edward makes a few steps forward.
4.04 sec

1:11:27 Minutes
Bella gets the rainmaker from the shelf and plays with it. She tells Edward she had had a chinchilla once and her mother and her had made such rainmakers with the chinchillas' excrements. They both laugh.
21.65 sec

1:15:41 Minutes
Charlie and the search party are running along the path. Then James and Laurent. Victoria appears, grabs James and the two of them start making out.
25.11 sec

1:23:03 Minutes
The Extended Version shows Bella and Edward on their way to the car.
Edward: "It's funny. Your father thinks you go to an all-girls school."
Bella: "Oh. that's not fair. Don't read Charlie's mind."
8.93 sec