These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
Alternate Character Interpretation: Does GLaDOS truly despise Chell, or does she truly care about her but is unable or unwilling to express it?
Breather Level: After being shot at nearly every time you turn a corner and open a door in chamber 16 you immediately have chamber 17 where the worst thing you may encounter is easily dodgeable energy blasts. And maybe regret over having to "euthanize" the companion cube.
Cargo Ship: Chell/Companion Cube is a popular shipping pair in the fandom.
The Rat Man's graffiti shows he was far too attached to his Companion Cube, and really didn't take having to incinerate it at all well.
The Lab Rat comic proves that he failed to incinerate it, carrying it around with him in his psychotic mania.
Creepy Awesome: GLaDOS, at least according to most of the internet.
McLain talks about the experience of being GLaDOS (including a very sexy voice, an unexpected burst of opera singing, and a scary laugh). Have a listen to some commentary.
The Weighted Companion Cube. It was intended to be this to begin with in the game, but even Valve admitted they vastly underestimated the extent to which it was adopted as a fan favorite.
The game itself was originally sold in "The Orange Box" with the much-anticipated Team Fortress 2 and Half-Life 2: Episode 2. Guess which one turned out to be the runaway hit and critics' darling? (Not that the other two weren't good themselves)
Everyone Is Jesus in Purgatory: There have been some truly odd interpretations of this fairly straightforward game as, among other things, a crushing feminist assault on the masculine and misogynist games industry. See the Wild Mass Guessing page for details.
Genius Bonus: Some people have deciphered the morse code tied to the new achievement. It appears to be GLaDOS rebooting.
More Popular Spin-off: It's hard to remember that Portal, which technically takes place in the Half-Life universe, started off as a pet project ("a little lagniappe", in McLain's words) that was included as a bonus game as part of the compilation The Orange Box.
Player Punch: We know who, when, and what caused it.
Rule of Cool/Rule of Fun: Quantum space holes that don't cause everything to be sucked into a black hole? Springs attached to ankles (with balls at the end near the arches) that don't cause immense and unimaginable pain? A science lab somehow receiving the funding for, not just one, but multiple Portal guns? Boots that allow you to not break every bone in your body? Who the hell cares, it's fun/awesome as hell!
That One Level: The Advanced Test Chamber 18 will have you tearing pieces of yourself out in frustration.
The Tetris Effect: Not only the game-fun part, but you'll find yourself wishing you had an Aperture Science Handheld Portal Device for real-life transportation. And planning out the most efficient way to get from here to the fresh-produce aisle. Thinking With Portals, indeed!
Yandere: GLaDOS' dialogue during the final boss fight seriously makes her seem more like a scorned lover than a crazed AI... of course, the two aren't necessarily mutually exclusive.
