1. When Alec tells Izzy that she looks good.
2. When they both say they love each other in the very first episode.
3. When Izzy correctly predicts that Alec would not approve of the mission.
4. When Jace suggests bringing Clary to the Silent City and the Lightwood siblings are like "Hell no!"
5. When they both make fun of Jace.
6. When Izzy wants some praise for interrogating Meliorn and Alec obliges.
7. The way that Alec hates being the distraction but Izzy loves it.
8. The two of them disagreeing about how long they can hold off the Vampires.
9. Izzy looking at Alec, who is looking at Jace, who is looking at Clary hugging Simon.
10. When Izzy sees that Alec is in a bad mood so she lets him rant until he feels better.
11. When Magnus gives Izzy the necklace in place of her brother.
12. When Izzy defends her brother to Clary.
13. Alec praising Izzy's negotiating skills so that Maryse will be proud of her.
14. Izzy defending Alec when Jace blames him for letting Clary get away.
15. Izzy defending Alec when their dad tries to blame him for all the "unsanctioned missions".
16. When Izzy warns her brother about their parents marriage plans for him.
17. When Izzy offers to get married so that Alec won't have to.
18. When Izzy breaks up with Meliorn and changes her style to take the heat off Alec.
19. When Alec is at Magnus' apartment so Izzy covers for him.
20. When Alec thanks Izzy for trying to take the heat off him.
21. Izzy and Alec arguing over who will be the distraction on this mission.
22. When Alec throws the name badge to Izzy and she catches it effortlessly.
23. When Jace doesn't want to leave Alec behind but Izzy has total confidence in her brother.
24. That one time Izzy agreed with her big brother and he was stunned.
25. That look the Lightwood siblings share while they're getting in trouble.
26. When Izzy tries to explain Alec's personality to Magnus.
27. Izzy being super protective of Alec after the Forsaken attack.
28. When Alec and Lydia announce their engagement and Izzy is really upset.
29. Both of the siblings trying to get Jace on their side but he's Switzerland.
30. When Alec is worried that Raj might have seen Izzy during Meliorn's rescue.
31. Alec arguing with Lydia when she arrests Izzy.
32. But Izzy stops him because she doesn't want her brother getting in trouble too.
33. The Alt World siblings were just as inseparable!
34. Alt Izzy insisted on going to Alec's party even when she got kicked in the face!
35. When real world Alec was willing to do anything to free Izzy.
36. He even risked destroying his Parabatai link with Jace to find it.
37. Izzy comforting Alec after he couldn't find the Cup.
38. When Alec tried to stay positive about their chances of delaying the trial.
39. This line: "I'm your big brother. Please, let me help you for once."
40. Alec putting aside his feelings and asking Magnus for help.
41. How proud Alec looked while Izzy was giving her speech about justice!
42. Lydia's speech about the Lightwood sibling's loyalty.
43. Izzy running into Alec's arms after Lydia withdraws the charges!
44. When Alec goes nuts on Jace for risking Izzy's life.
45. When Alec tells Izzy that Clace returned the Mortal Cup so she is free!
46. Alec giving Magnus his bow and arrows in exchange for his help.
47. Izzy basically planning the whole wedding for Alec.
48. This line: "Sisters can really drive you nuts sometimes!"
49. When Alec thanks Clary for saving his sister.
50. When Izzy is constantly trying to get Alec and Jace to talk to each other!
51. Izzy asking Simon for help because she wants to throw the perfect bachelor party.
52. When Izzy tricks Jace and Alec into resolving their issues!
53. Izzy looking worried during the wedding.
54. When Izzy secretly invites Magnus to the wedding!
55. Izzy being so proud of her big brother!
56. Alec looking very pleased that his little sister is proud of him!
57. When Izzy is suspicious of Camille so she calls Alec.
58. This line: "And her freedom requires a lip lock?"
59. Izzy staying with Magnus and Camille to make sure there's no more kissing!
60. Every time Alec and Izzy were in charge of "checking the perimeter".
This list is so long because Alec and Izzy are so awesome!
What has been your favorite Lightwood siblings moment this season?