Jake insisting he'll only help the police solve a case if Leslie gets her job back.
Jake and Des are trying to defuse a bomb, and Des tells Jake that he should leave since Des doesn't want to kill him if he screws up. Jake replies "As annoying as I find you, I would never let you die alone." Veers into Tear Jerker territory at the end of the episode, where Jake is comforting Des as the latter lies shot on the tarmac and bleeding out.
Des' father telling Jake that Des constantly talks about him, and regards him as a role model/surrogate father.
Des buys the remains of Jake's GTO and gets it repaired for him.
A meta example: Allan Hawco announced that Lynda Boyd (Rose) would be joining Facebook, and asked the fans to give her a warm welcome. They happily obliged, and Boyd personally replied to some commenters thanking them profusely. She was quite overwhelmed by all the support and love she received, and regularly interacts with fans (she calls those on Twitter her "Tweetiepies").
In the season five opener, everyone's reactions to finding out Jake is alive.