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.
YMMV: Penny and Aggie
Arc Fatigue: "The Popsicle War" stretched out so long that many readers expressed concern over the extreme length of the plotline, which dominated most of the year it ran. Subsequent plots have been much shorter, with larger story arcs broken into more manageable chunks.
Base Breaker: Aggie, Daphne, Helen, Lisa, Marshall and Stan have been these, for varying lengths of time and to different degrees, as is clear from debate on the comic's forum.
Aggie: Principled activist, or preachy hypocrite?
Daphne: Genuinely loving towards Sara, and genuinely sorry for once having believed the worst of her? Or spiteful, jealous ditz who's only interested in Sara for the sex?
Helen: Misunderstood woobie, or spiteful, self-pitying traitor?
Marshall: Essentially kind and patient guy who means well? Or wangstyEmo Teen who can't get past his Mommy Issues? Unlike with Lisa, the fandom grew more negative to his perceived blandness and wussiness over time, despite the fact that T Campbell liked the character.
Stan: Genuinely repentant, former self-centered user who at least tries to act more selflessly, even if he doesn't always succeed? Or perpetual Jerkass whose attempts at reform are merely cosmetic?
The endgame Relationship Upgrade: Inevitable, or shameless Fanservice? Do the title characters have chemistry as a couple, or does their relationship seem forced?
Complete Monster: Cyndi is a manipulative sociopath who almost gets off on driving people to suicide. In a really creepy and incriminating file on her laptop, she documented how fun and easy it is to dig a hole into someone's psyche and widen it. She brags about nearly driving Michelle into starving herself to death and she had plans to destroy Daphne and Sara's relationship in the hopes of getting one or both of them to commit suicide. In the same strip this was all revealed, she successfully goaded Charlotte into slitting her own throat by using her Mommy Issues against her. Seeing someone bleed out in front of her thanks to her words puts a grin on Cyndi's face. What's even more damning is that both her biggest "success" so far AND her next intended victim, who she merely considers "practice" (Meg), are erstwhile members of her own clique from the "Popsicle War" arc.
Creator's Pet: Marshall was beloved by T Campbell, but not so much by the fans. One fan poll had him rated very low, and T himself has acknowledged that most people just didn't care for him.
Ensemble Darkhorse: Duane shows unexpected nobility, wisdom and charm towards the conclusion of "The Popsicle War" and in ":-)" Lisa is just so... her. Jack Kirk, despite his silent and self-deprecating nature, will surprise you with his wisdom and pragmatism.
Fanon Discontinuity: Fans dissatisfied with the strip after "The Popsicle War" have declared everything past that point to be this trope. They use the fact that T Campbell initially considered ending the strip there as justification.
Ho Yay: Virtually a defining concept of the strip - Two openly gay relationships, and the numerous characters that simply have the subtext, such as the main characters themselves. Even characters who had shown virtually no hints of homosexuality often have "twinges" towards it at certain points.
Moral Event Horizon: Cyndi's manipulating Charlotte into attempting suicide. Many fans felt she'd already crossed that horizon in "The Popsicle War," when she exploited Michelle's body issues and manipulated her into developing an eating disorder, though it was also hard to tell at that point in the story whether she was deliberately doing so out of pure evil or whether she was simply a puppet of Karen. "Missing Person" confirmed that she was a willing participant and actually wanted to go even further.
Nightmare Fuel: All of Chapter 3 of the Missing Person arc. Page 12 may well cross the line into beyond terrifying, but pretty much every page has something horrifying on it.
Painful Rhyme: "Boys find it way sick when those girls get Lasik."
The Woobie: Charlotte, who despite being a psychotic religious fundamentalist, is heavily implied to have had something traumatic in her past which might have stemmed from an abusive father and at some point might have included a rape. Whether she really is this or not is actually a point of debate between some of the characters in the strip. It says something for her that even when she was trying to kill Cyndi to prevent her from ever hurting anyone else again, she's still presented sympathetically.
The whole cast has shades of woobie from time to time. Hell, Karen's broken gaze into the past at the end of the War is sad, even when she was such a horrid witch. Also, Helen, for whom becoming part of the Something Positive cast was actually a step up for her.
T confirmed in the forum that Charlotte was, in fact, sexually abused.