In the episode The New Normal, Emily is accused of favoritism for her being a lesbian by Paige's father because she was chosen to be captain. When Emily's mom finds out about this she tells him that Emily deserves it because she is the more talented swimmer and worked hard for it. Emily's mom then tells that her she cares about her and will always be there for her even though she doesn't agree with her daughter. Cue Emily hugging her mom and thanking her.
In the episode "Over My Dead Body," Emily (possibly) dreams of Alison comforting her; Alison tells her that she misses Emily the most and that Emily was always her favorite, before kissing her. It's the nicest we've ever seen Alison and it's especially poignant given that Emily was in love with her.
In "Eye of the Beholder", when Hanna goes to the DiLaurentis house and finds it on fire with Jenna Marshall inside, she charges into rescue her without any hesitation. Pretty big of her, doing that for someone who she suspects is stalking/blackmailing her.
Spencer tops the above with her Take My Hand moment in "UnmAsked". Basically, she tries to save the life of someone she knows stalked and blackmailed her and tried to kill her.
A minor one from "It Happened That Night": Hanna visiting Mona in Radley Sanatorium, trying to fix things between them.
Caleb: And for the record, Hanna, I'm gonna protect you from A. I'm not asking for your permission.
When the three liars confront Spencer about her apparent betrayal. Not only are they not willing to believe she had betrayed them, she actually tells them the truth about what is going on. I had expected the show to throw in a twist, but no, just four best friends who trust each other despite all of the terrible things that have happened to them.
"A is for A-l-i-v-e":
Hanna and Mona, brought together by their current situation, are hanging out and shopping together like old times. After the shopping trip, Hanna tells Mona that she had fun. Mona responds that she knows Hanna didn't really have fun and that she was only hanging out with Mona to get the incriminating video of Ashley that Mona pulled out of Detective Wilden's car. What does Mona do next? She hands over the chip with the only copy of the video on it and advises Hanna to burn it. No blackmail, no demanding anything in return, none of the usual Mona tricks. She just gives it up. The whole moment is capped off by what she says to Hanna before leaving:
Mrs. Grunwald confirms that Ali is alive, but tells the girls that she's trying to figure out who she can trust. Their response is basically that Ali can trust them, no matter what. Even though Emily is the one to say it aloud, it's clear that she speaks for all of them.
Hanna asking Caleb to stay in Ravenswood and help Miranda at the end of "Grave New World", especially since she acknowledges that Miranda is beautiful enough for him to fall for, but she trusts that he won't.