Inspector Lynley/Heartwarming

"A Great Deliverance":
- When they're sitting in the pub going over case notes and discussing how to deal with the annoying Yorkshire policemen working with them, and they plot to make them dig up the entire farm as revenge. It's the first moment we see them truly getting along, and though it doesn't last, it foreshadows just what their relationship will become.
- When Barbara tactfully rescues Lynley from an awkward encounter with his Unrequited Love and her husband.
- Lynley comforting Barbara at the end of the case when she confesses what happened to her little brother, telling her "You're not a monster," and handing her his handkerchief.
"Payment in Blood": Lynley is convinced he's acted unprofessionally during the Case of the Week and tells Barbara he's thinking of resigning. Her flat response? "You resign, I resign."
"Missing Joseph": "One thing you are not is an inadequate human being!"
"Deception On His Mind": Barbara and Lynley, at the end.

Lynley: You saved our lives out there. It was an amazing thing you did.
Barbara: I wanted to kill her. [she sniffles] You know, I was so proud of working with her. She was everything I ever wanted to be.
Lynley: [holding back tears] Sometimes people let you down.
Barbara: You haven't. Ever.
[cue meaningful Held Gaze]

"A Traitor To Memory":

Havers: Weberly wants a coverup, and he's relying on your loyalty to him to get it.
Lynley: No, see, that's the thing I think you've got wrong. I think he's counting on my loyalty to you.
Havers: To me?
Lynley: [nods, smiles]

- And then immediately after:

Lynley: You are not meant to know this. Weberly wanted to have you sacked. I had to persuade him to let you stay. Which is why I wasn't going to let you throw it all away. [hands her her resignation letter]

- And also:

Lynley: All I'm saying is, if you're leaving - if you're really leaving - I'm going to miss you.

- This is capped off by the final moments of the episode, with the two of them standing next to a bonfire. After they've finished burning what they came there to burn, he turns to go - and she stills him by placing a hand on his chest, then throws her resignation letter into the fire. No words are exchanged. They don't need to be. From that moment on, their trust in each other is absolute.
"A Cry for Justice": The look on Lynley's face when Barbara tells him she's been reinstated.

Lynley: Oh, Havers. That is... that's... [beaming smile]

"In Divine Proportion": Barbara is held hostage at gunpoint - on her first case back after taking a bullet to the stomach in the series 3 finale. She's terrified out of her skin, but largely keeps in control until she is rescued - at which point she whales the tar out of the hostage-taker until Lynley pulls her off, then bursts into tears and cries herself out against Lynley's chest as he holds her. The kicker? He kisses the top of her hair as she cries. The scene, in full, is here.
"Word of God": Lynley shows up at Barbara's flat in the middle of the night. Heartfelt and emotional baring of souls ensues, concluding with the mutual admission that they are each other's reason to get up in the morning.
"Natural Causes": "I couldn't have wished for a better colleague - or friend."
"Limbo": "Welcome back, you."