* In the ''Lab Rat'' tie-in comic, it's revealed that [[spoiler:Chell was chosen as a test subject by Doug Rattmann,]] despite her file listing her as being rejected. Why? [[spoiler:Because, according to her file, Chell is abnormally tenacious. [[{{Determinator}} She never gives up. Ever.]]]]
* [[spoiler:In the last moment of the ending to ''Portal 2'', [=GLaDOS=] sends up an old friend to join Chell as she leaves for the surface: the Weighted CompanionCube!]]
** [[spoiler:And it's the ''same'' Companion Cube from ''Portal'', not the newer design from ''2''. The old design is just barely visible, beneath the chars from being in the incinerator.]]
* The credits song in ''Portal 2'' has [=GLaDOS=] sing that [[spoiler:she no longer wants to kill Chell and lets her leave, even though she calls her fat...[[RunningGag again]].]]
** And before that, [[spoiler:[=GLaDOS=] pulling Chell back from the moon portal.]]
*** Especially since she could have finally accomplished her original goal of [[spoiler: killing Chell (by letting her fly off into space), and yet she chose to save her life and set her free instead.]]
* [[spoiler:[=GLaDOS=]'s genuine relief and happiness to see Chell is okay after pulling her back from the moon.]]
* Debatably, [=GLaDOS=] [[spoiler:defending Chell against Wheatley's insults--the exact same insults she herself used earlier. "Look at her, you moron. She's not fat."]]
** Even better: [[spoiler:"And what, exactly, is wrong with being adopted?" Which she immediately spoils by whispering "For the record, you ARE adopted, and that's terrible. But just work with me here."]]
** Any time [=GLaDOS=] acknowledges you as a worthy rival, even if it's to spite Wheatley. "You didn't do anything. ''She'' did all the work."
** [[spoiler:Less spoiled by [=GLaDOS=] earlier [[http://www.youtube.com/watch?v=XW-F10Q80kk telling you]] that the potato she's in doesn't produce enough power for her to create lies. [[AlternativeCharacterInterpretation She might have been saying that she thinks it's terrible that Chell is adopted, not that she's terrible for being adopted]]. Unless the bit about her not being able to tell lies anymore was a lie. Or unless the extra half-volt she gets from the portal gun gave her enough energy for lying.]]
** [[spoiler:Or maybe if you buy both '[=GLaDOS=] is Caroline' and 'Chell was Cave's and Caroline's adopted child' theories, she is saying that it's terrible Caroline HAD to adopt Chell, because that means something happened to her real parents.]]
** [[spoiler: Or if you go with Caroline being in the potato with [=GLaDOS=] (not [=GLaDOS=] herself), and the idea that Cave and Caroline are Chell's ''real'' parents, [=GLaDOS=] could be genuinely saying that it is terrible, because Caroline had to give Chell up since she was going to be uploaded into [=GLaDOS=].]] Both Heartwarming and a TearJerker.
* [=GLaDOS=]'s response to Cave Johnson's pre-recorded last words:
-->''"Goodbye, sir."''
** The fact that her response was so automatic and instinctive; some of her small talk with Chell suggests that she doesn't completely remember Cave, but that response implies that something inside her is still loyal to the man she/[[spoiler:Caroline]] loved and admired.
* Earning the "No Hard Feelings" achievement. The Oracle Turret's quiet, desperate plea of "I'm different" and its subsequent thankfulness upon being rescued really make the moment.
** Which may turn into MoodWhiplash if you then accidentally [[VideoGameCrueltyPotential (or purposely)]] push it through an Emancipation Grill or drop it down the pit.
* The ending to the co-op campaign. [[spoiler:Atlas and P-Body succeed in opening the giant vault, and inside are thousands upon thousands of human test subjects in cryogenic stasis. Even though the only purpose to finding them was that so [=GLaDOS=] could resume her human testing, and it's fairly obvious that most of them are doomed to die during said testing, the fact that [=GLaDOS=] herself is so unbelievably ''overjoyed'' turns it into a genuine heartwarmer.]]
--->[[spoiler:'''[=GLaDOS=]''': You saved science.]]
** [[spoiler: "You did it. You really did it. All that testing was worth it! Look at all those test subjects! Think of all the testing! You saved science." [=GLaDOS=] might be a poor little passive-aggressive A.I. with psychotic tendencies, but ''damn'' if that line doesn't sound like she's ready to ''cry'' from pure happiness.]]
* [[spoiler:The little space-obsessed core]] at the end of ''2'' gets his fondest wish, and he sounds absolutely overjoyed.
** Which could have been [[TearJerker gut-wrenching]] instead if they had left in some DummiedOut lines.
--->[[spoiler:'''Space Core''': Earth. Earth. Wanna go to Earth. Too much space. Don't like space. Wanna go home.]]
* During the ending credits of ''2'', [[spoiler:[=GLaDOS=] [[http://www.youtube.com/watch?v=dVVZaZ8yO6o sings about not needing anyone]] anymore (though she could easily be in denial), and that she might delete Chell from her memory.]] The lyrics for one line read "REDACTED," and the sound becomes a bit garbled, but the words are still easily audible: [[spoiler:"When I delete you maybe/I'll stop feeling so bad."]] Plus, the subtitles (if they're turned on) give the line away, anyway. [=GLaDOS=], you big murderous softy!
* The fact that, after everything that happens in both games, after all the hell that [=GLaDOS=] and Chell have put each other through, [[spoiler:after stopping Wheatley from letting Aperture Science go up in a nuclear fireball, [=GLaDOS=] honestly, truly, no strings attached, ''lets Chell leave''.]]
* Part of the ending to ''Portal 2'' where [[spoiler:all the turrets stare at you as you rise to the surface...and they all sing the most gorgeous song. [=GLaDOS=] may claim she still hates you, but the other beings in Aperture Science Testing Facility make it very clear that they are grateful for everything you've done for them. (Even if it involved [[EasilyForgiven you]] knocking a few of them over.)]]
** It gets even more heart-warming when you look at the English translation of the Italian lyrics:
--->[[spoiler:Dear beautiful, my beautiful darling!]]\\
[[spoiler:My child, oh Chell! [pun: "oh heavens!"] ]]\\
[[spoiler:For I hold her in esteem...]]\\
[[spoiler:For I hold her in esteem.]]\\
[[spoiler:Farewell to my dear!]]\\
[[spoiler:My dear girl,]]\\
[[spoiler:why do you not walk away?]]\\
[[spoiler:Yes, far away from Science.]]\\
[[spoiler:My dear, my dear girl?]]\\
[[spoiler:Ah, my beautiful!]]\\
[[spoiler:Ah, my dear!]]\\
[[spoiler:Ah, my dear!]]\\
[[spoiler:Ah, my child!]]\\
[[spoiler:Oh dear, my dear...]]
** This is particularly poignant if you believe that [[spoiler:Caroline was Chell's mother and lives within [=GLaDOS=] (as mentioned in the credits song), and thus Chell is, in a sense, [=GLaDOS=]'s adoptive daughter, [[MyBelovedSmother in an overbearing kind of way]]]].
*** Some of us think it's more poignant if she's not.
* Spoilers for the ending of ''Portal 2'', and not explicitly canon... but come on. [[http://rain.nxe7.com/ Tell me this doesn't put a smile on your face.]]
* During the final test for the Hard Light Bridges portion of the Co-Op Campaign, Atlas and P-body are faced with a problem with a relatively simple execution: [[spoiler:cut the bridge so that they fall into a portal and get flung onto a catwalk. As it turns out, the velocity can cause them to overshoot the catwalk and fall into the abyss below. What do they do? Use each other as a wall so they stop right on the mark.]] Shortly after, Atlas hugs P-body, cementing their already developing friendship.
** The trailer has a similar hug moment: [[spoiler: [[http://www.youtube.com/watch?v=A88YiZdXugA Atlas inadvertently smashes P-body, who is then rebuild just behind him, showing that neither can actually die. P-body waves calmly at his friend and Atlas hugs him because he's just so glad he's alright.]]]]
* [=GLaDOS=] showing [[spoiler:what seems like genuine relief at Chell's survival at the end of ''Portal 2''? [=GLaDOS=] admitting "I thought you were my greatest enemy, but all along you were my best friend"? And finally - after insisting that she's totally just getting rid of you because it's less trouble, okay - giving back the original Companion Cube?]]
--> [[spoiler:Oh, thank ''god!'' You're all right!]]
* Just the fact that [=GLaDOS=] [[spoiler:waits until Chell wakes up and it can be confirmed that she's all right before she deletes Caroline. We don't know how long it took Chell to wake up, but it certainly was long enough to fix the chamber.]]
** It had to have been several hours since [[spoiler:it's night when you defeat Wheatley, and day when you leave the facility.]]
* Wheatley's apology. [[spoiler:From space.]]
* The [[AwesomeMusic/{{Portal 2}} song]] [[https://www.youtube.com/watch?v=dg3JakqJWHU "Love as a Construct"]] from ''Portal 2'' for the Companion Cube is very sweet and oddly touching, in its beepy electronic way.
** ''Love as a Construct'' nothing, [[https://www.youtube.com/watch?v=reSMFE-TeV8 ''Exile Vilify'']] is the most heartwarming thing in the entire Valve [[BodyHorror body of]] [[AndIMustScream work]]. Just imagine it playing at the end of the Lab Rat comic, as Rattmann peacefully goes to sleep...
** Similarly, listen closely to the song's tune. [[spoiler:It's the same one the turret opera uses.]]
** Yes, that song's associated with love in this game, it's so sweet how the Companion Cube hums it just for you!
*** And if you listen carefully, you can also hear it being played (very softly) as Chell is losing consciousness [[spoiler: after [=GLaDOS=] pulls her back in]].
* Listen to the end song, and listen carefully. Notice a slight difference in the [[spoiler:two last "that's what I'm counting on" parts and the very end of the song? Notice how it sounds like two voices singing together?]]. That's because [[spoiler:it ''is''. It's not just [=GLaDOS=] singing there... it's ''[=GLaDOS=] and Caroline''! [=GLaDOS=] actually decided to let Chell's human mother (if you go with the "Caroline is Chell's mother" theory) sing along with her, as [=GLaDOS=] kind of considers Chell her adoptive daughter. In short, "Want You Gone" is more than just a [=GLaDOS=] ending song, it's the two mothers singing a farewell to their daughter.]] If ''that'' isn't heartwarming for Portal, I don't know ''what'' is!
** In this case, "Want You Gone" means "I want you out of this shithole of a place and somewhere else." Which every animal parent does: push their children out of the nest.
** Which also may explain their hatred for a certain type of animal, what animal is well known for pushing their children out of their nests? Birds.
* Another from the ending song: "Under the circumstances I've been shockingly nice." That line makes one realize that [[spoiler:[=GLaDOS=] really was much nicer in the second half than one would really think her capable of being.]]
* Another point about the ending song: In the second verse, [=GLaDOS=] sings, "Now little Caroline is in here too". The next two lines, on the other hand, are "One day they woke me up/So I could live forever". Those two lines [[spoiler: aren't sung by [=GLaDOS=]... it's ''Caroline'' who's singing those. Not only did [=GLaDOS=] let Chell's human mother sing parts in a duet with her, she ''gave Caroline her own solo part to tell what happened to her - being woken up within [=GLaDOS=] so that she could live forever''.]] Not only that, but the next line is "It's such a shame the same will never happen to you", which might in fact be [[spoiler: light sarcasm from [=GLaDOS=]]]. Basically that whole part is telling Chell: [[spoiler: "We're stuck together because of that failed BrainUploading, and we don't want that kind of thing to happen to you, so go and live your life freely"]]. Heartwarming and a TearJerker when you really think about it.
* [[http://www.youtube.com/watch?v=o8SdYz7cq04 Proposing with Portals.]] I '''dare''' you to do something half as romantic.
* [[http://www.youtube.com/watch?v=NorZUFfpvC0&feature=related This live-action short film]], which is set after the original ending of the first game. At first, it just seems like it's about her having [=GLaDOS=] flashbacks and trying to survive, [[spoiler:but then she finds the cake book and sheds tears of joy. She spends the rest of the movie baking cake. Even better is what she writes on her wall.]]
--> [[spoiler:"I get to have some cake today! The cube is watching me.]]\\
[[spoiler:I hope it's proud to see me now, Outside, Alone but free!!"]]
* The [[http://youtu.be/B7Ax18kldUo ending]] of the new DLC "Art Therapy" co-op course, where [=GLaDOS=] [[spoiler:adopts the baby birds]]. Even though the scene is tinged with the same abrasiveness and fridge horror [=GLaDOS=] usually brings to social interaction, her [[spoiler:bending down over the incubator as a doting mother is very sweet...even if the insinuation of the scene is she has insidious plans involving them]].
--> [[spoiler:[[AC:Look at those cold avian eyes. Those talons. Those razor-sharp beaks. You're little killing machines, aren't you? Yes. Go to sleep, my little killers. Mommy's got a big day for you tomorrow.]]]]
** But what ''really'' makes the scene: [[spoiler: did anyone else think of Chell while watching the one bird peck at its glass enclosure?]]
** Before that, [=GLaDOS=] congratulating Atlas and P-Body [[spoiler: for shooing the bird out of the facility]]. She seems genuinely proud of them.
--> ''[[AC: Nice hustle... [[spoiler:kill machines]].]]''
* Chell running into her old science project. It might very well have been the last thing she actually got to ''do'' in her normal life. And now, all those years later, after being put through hell, Chell sees her little potato again - and it's well on its way to becoming its own ecosystem. There is no way that didn't cheer her up at least a little bit.
* Cave Johnson's pre-recorded message where advises the homeless test subjects to not waste the sixty dollars they'll be getting later. Granted, the message is superficially just as insensitive as any of his others, but there's literally no reason for him to have recorded this besides being, on some level, concerned for his test subjects' well-being. It's a subtle touch that goes a long way to make his character more sympathetic.
* Rick the Adventure Core is one of the only people to unconditionally compliment Chell. Even though he is a sleazeball, it's very cute how he straight-up calls her beautiful upon seeing her for the first time.
* The ending of ''Portal 2'' [[spoiler: has Chell emerging into a huge field of wheat with a beautiful blue sky above her.]] How is this heartwarming? [[spoiler: Portal takes place in the ''VideoGame/HalfLife'' universe. And considering how bad the ecosystem looked in ''VideoGame/HalfLife2'', the state of things now certainly seems to suggest that the Combine were defeated.]]
* Two of the pre-recorded messages from the announcer from the first chapter are directed at any survivors of a post-apocalyptic world who happen to discover the facility, welcoming them and telling that "testing is the future, and the future starts with you!" Another earlier one uses the phrase "when society has been rebuilt." There's something really heartwarming about Aperture's boundless optimism, especially in regards to what they assumed would be a post-apocalyptic world.
** There's also this bit. Never has RagnarokProofing felt so uplifting.
--> '''Announcer:''' Well done. The Enrichment Center reminds you that although circumstances may appear bleak, YouAreNotAlone. All Aperture Science Personality Constructs will remain functional in apocalyptic, low power environments of as few as 1.1 volts.