When Holmes is ill, he has nothing but time on his hands and takes to remembering his past. It's a "scene" that goes back and forth between heartwarming and Tear Jerker (as are much of the sentimental, etc. moments of the book).
As is not an uncommon in Sherlockian Fan Fic, Holmes's memories reveal that he once had a sweetheart. The one flashback featuring Anne Middleton is bittersweet, because the reader already knows that Annie died before the events of A Study in Scarlet.
Nearly thirteen years later, he lay shivering on a floor as cold and hard as that tombstone and dreamt of her, his exhausted mind finding solace in memories of younger, brighter days.
Though Mycroft is an Aloof Big Brother in terms of plot dynamics, he is by no means aloof in characterization. He gets a Manly Tears/Heroic BSOD moment in the mortuary when he believes his brother dead, recalls Sherlock's childhood with fondness, shows himself to be Not So Stoic when examining a ravaged murder victim, gets comforted by Mrs. Hudson, and hovers protectively around his invalid brother. Really, Mortality could be considered a Crowning Moment of Heartwarming for a character who rarely gets heartwarming moments inside and out of the Canon.
The A Mother's Heart collection (two stories only at the time of this writing) is family fluff all the way, a Crowning Moment of Heartwarming for the Watson family.
The Yarders regarding Watson as one of them. Cue those awww's!
In the first tenth of One Hundred Sentences, Holmes's implicit trust in Watson during the events of "The Adventure of the Empty House": no evil would touch him while Watson stood guard..
One Hundred Sentences was written before Season 2 of Sherlock was released, but the following sentence bears a strong resemblance to The Reichenbach Fall:
It was not fear for [Holmes's] own skin that kept him silent to Watson's cries at Reichenbach — it was fear for the life of the "best and wisest man" he'd ever known.
Going completely against the author's tendency to make a Tear Jerker out of Holmes's time in Tibet is this:
The newspaper clipping announcing the birth of Arthur Sherlock Watson left him happier than he'd been since he could not remember when, and, for the first time in a long time, he went to sleep with an untroubled conscience, knowing that his ruse was keeping a baby boy safe, thousands of miles away.
Just the running mentions of Wiggins throughout One Hundred Sentences, as he sticks with Watson throughout the Hiatus years.
The happily-ever-after of One Hundred:
The problem of how their relationship would go on haunted them merely for a matter of days after Holmes's return, for they were swiftly swept back into the unfinished war — and in the process, a fresh and stronger bondwas forged between them, a new understanding, and it continued to the end of their days.