Korsak in "Remember Me" holding Jane as she finally lets out the repressed fear and pain Hoyt inflicted on her.
Jane and Maura's entire friendship and how they only stay mad at each other for a couple of episodes before making up with a hug and saying "I missed you" to each other.
Jane telling Angela she does have a doctor in the family.
Frost Mother visit's town to tell him she getting married...to a woman. Before she can tell him he notices the engagement ring and toasts her, revealing he's known for years and had just been waiting for her to tell him.
Two for "No One Mourns The Wicked". First, the end scene where the gang is all sharing a drink on Korsack's porch after they'd just saved Korsack from a pair of serial killers. They all look so comfortable in each other's company, despite the terror from earlier in the day at that same house. The second is that when the episode aired, it was dedicated to the memory of Lee Thompson Young, who played Det. Barry Frost. Because, while "No One Mourns the Wicked", it is quite clear from the statements of the cast and crew that he will be missed.
Tommy hires a lawyer everyone else seems to consider comparable to hiring Lionel Hutz to help him get a settlement from the parking garage collapse of the season three finale. At the end of the episode, it turns out he won the settlement - and used the money to pay off Angela's IRS debt.