How Kasumi comforts Tali after Utukku, by reminding her of how Keiji left her
Kasumi:The last message Keiji ever left me told me that he wanted me to go on. To be happy once he was gone. He knew when he recorded it that he'd likely be dead within hours, but that was what mattered to him. To tell me to be happy because he loved me. If Shepard could have done so... I know his message to you would have been the same.
Thane comforting Tali during the siege of the Citadel while trying to talk her out of burying her emotions like Thane did after his wife died.
Thane: "Only that the pain you feel is familiar to me. I know you wish to shut it out. To take revenge for his death. But I do not believe Shepard would have wanted that path for you. And as one who experienced it... I would agree."
Shepard taking some time to pet Urz after the battle for the Citadel. That section is seen from Urz's POV, and he's very happy to have his pack back together.
Tali and Shepard's Big Damn Kiss at the conclusion of the Rannoch arc.
The final lines of Requiem's epilogue, and by extension the final lines of the story that had been ongoing for six and a half years:
"Every moment I have is yours. We all have time now. Whatever happens, it was worth the cost, and I know each of them would say the same." Shepard replied, brushing her cheek with his free hand before leaning down to kiss her properly.
Shepard was right. They had lost so many friends and loved ones, but this was their requiem for the lost. Living the life they had earned through all the blood and tears. Some had given all so that they could stand where they now stood, looking out at the galaxy not with trepidation, but with hope. Holding one another close not out of fear or desperation, but out of love. That was their greatest legacy.
They looked into each other's eyes and Tali felt the first rays of sunlight touch her face as Urz stirred at her feet. With a shared smile they turned towards the mountains and the glow that was cresting their peaks. Warmth and light spread across the plains as the dawn finally came to Rannoch, pushing back the chill of the long night.
Together they stood in silence and watched the sun rise.