When Heatwave preformed a non-fatal Diving Save to catch the falling Robo-Baby in "Four Bots and a Baby".
"Don't worry little guy, uncle Heatwave's gotcha."
Watching both humans and bots getting into the Christmas spirit while playing in the snow in "Christmas in July". There's nothing like watching ancient alien beings from beyond the stars... throwing snowballs and making snowmen.
Dani, Kade, and Graham reminiscing about the times they went fishing with Charlie, feeling bad about dodging the fishing trip, and deciding to go to the pier to try and spend some time with their dad and Cody.
Optimus Prime thanking Cody for all the help he's given the Rescue Bots.
The ending of "Bumblebee to the Rescue". Blades hugs Bumblebee!
After Chase gets eaten by the Squlish in "You've Been Squilshed", Chief Burns reveals that he considers Chase as more than just co-worker, he considers him family.
Chief Burns: (stops Graham before he goes off the fight the Squlish) And be careful, I'm not losing any more of my family today.
Near the end of "Shake Up" Heatwave nearly gives away the bots secret to a trapped Frankie while trying to protect her from some falling rocks.
Heatwave: Huh, so now you know our secret. But if we've learned anything by being on this planet, a life is more important than our cover. (looks to see Frankie is unconscious).
Later Frankie reveals that she may have heard him after all.
Frankie: Thank you Heatwave.
Heatwave's reaction when the probes got Cody in "Countdown" was very heartwarming, he even gave a Big "NO!". It's nice to see he doesn't want any harm to come to his young human friend.
How Dani ultimately talks Blades through his fear of heights. She doesn't urge him to brave through it, remind him of the severity of their situation, or push him in the slightest. She only reassures him that "I'm not going to let anything happen to you", and that it's okay if he goes slow.
Blades manages to return the favor to a frightened alternate timeline version of her when she gets scared that they'll both get chopped up by some wind turbines.
Frankie, meeting her idol Dr. Elma Hendrickson in 1939, and giving her a hug. Not many people can say they met one of their childhood heroes in person.
Right before Cody left the alternate present, Dani had this to say:
Dani: If I had to have another brother, I'd wouldn't mind it being you.
After Doc Green reveals that he knows the truth about the bots being aliens, the rescue bots themselves seem perfectly comfortable that he knows their secret.
Every time Cody and Frankie have a sweet moment and especially when they hug.
Like at the end of "Sky Forest", when Frankie split her first place medal from the Science Fair. Then gave the other half to Cody.
As out of character as it was, Doc Morocco actually saving the lives of the Burns family in "Tip of the Iceberg" counts. His later sending Chief Burns the portrait of his grandfather Captain Burns was surprisingly generous as well. The latter gets sour when we learn it serve a double purpose in "Changes".
Boulder getting through to monster!Graham in "Feed the Beast", showing they're good partners and close friends, with monster!Graham even saving Boulder from the volatile explosive chemicals
The Burns' and the others relief that Chase was only pretending to be a bad guy in "Bots and Robbers".
The ending for "Odd Bot" out.
Whenever Optimus became feral in "Big Game", Cody talked him down each time. Even managing to talk him out of harming Quarry, who at that point had done nothing to deserve any mercy.
When Dani reveals that Captain Ambrose made it back to 1915 and married Lillian at the end of "Phantom of the Sea".
Ira's positive reaction to the Bots in "Did You See What I Thaw?".
Not only did Ira's tribe befriend some ancient Autobots. But the ancient Autobots even went out of their way to protect the tribe from some meteors. Which is very impressive when you take into account those Autobots had to deal with an army of Predacons and their Decepticon masters.
Blades and Dani's duet about how while Dani loves flying, Blades hates flying... but he has fun flying with Dani.
From the ep "Today and Forever".
Optimus Prime: That has been my goal as well, Francine, and Griffin Rock has been an excellent testing ground.
Heatwave: But won't humans be afraid of us?
Optimus Prime: Not if your actions are true. You may look different, but you are fully a part of the Burns family. They are in your spark, and you are in their hearts.
Doc Greene asking Professor Baranova to marry him.
Pretty much any interaction between Mayor Luskey and his wife. Normally with a couple like them, you would expect Mrs. Luskey to be a trophy wife and only with the mayor for his power and wealth, but there's never any indication that either one isn't genuinely in love with the other.