1) Alecs last memory, because it shows Castis Vakarian and he mentions Garrus and Shepard. I am a Shakarian girl and this came out of the sudden for me. Also it was special, because of Garrus and his father not having a close relationship and I always wondered how things went between ME2 and ME3. Garrus tells Shepard that he talked to his father to get support against the Reapers.
2) Meridian. I loved the final battle, although the bossfight is kind of disappointing. But the whole thing around it. Meridian itself, all the help and support that arrives and the feeling of finally REALLY fighting for a new home and survival.