Anthony Caine of For Better or for Worse. Once Lynn Johnston decided to bring Liz "back home" and pair her up with her nice-but-dull first love, Johnston made every effort to make the reader love him as much as she obviously did, including retroactively vilifying his ex-wife, Therese, in the process. This extended to her having Liz's father, John, the strip's patriarch, explicitly put down Liz's other boyfriends, and fawn over Anthony. The readership largely rejected this, as signified by his nicknames "Blandthony", "Granthony" and "That Fucking Mustache Guy". This also suffered badly from Values Dissonance; the main attempt to villify Therese was her being upset that Anthony lied to her about his willingness to raise the baby he badgered her into having while he was being blatantly emotionally unfaithful. He's also supposed to be sympathetic for his wife acting like he's cheating on her when all he's doing is... er, cheating on her.
Frank - ostensibly the central character of Liberty Meadows. At first just the foil for the antics of the Funny Animal cast, towards the end of the strip's newspaper run, he became more and more the focus of events, particularly lead female Brandy's wedding. As the strip made it more obvious that Frank and Brandy were meant to be together, there were fewer and fewer answers to the question "Why, exactly?" Especially given that A) Brandy's fiancé was everything Frank wasn't (rich, good-looking, smooth, and actually able to tell Brandy how he felt) and B) Brandy had already told him he'd blown his shot with her by being wishy-washy.
Luann: Mr Fogarty, Luann's teacher. Greg Evans dedicated a full three weeks of story to him announcing his retirement (from a job he hates and is terrible at). And within the strips were "flashbacks" showing bits from past stories, emphasizing exactly how one-note he is. And every day a note reminded readers to follow a Web link to see even more of these past stories. It's doubtful anyone except Evans himself cared much about Fogarty leaving, certainly not enough to go skimming through old storylines just to see numerous examples of him being ignored and disrespected by the students. The "shilled by other characters" part comes into play when the students (Tiffany included) throw him a surprise retirement party, even though the idea of them showing him attention or gratitude goes against 25 years of canon.
Peanuts: Spike (Snoopy's brother) and Rerun (Lucy and Linus's younger brother). Both debuted in the 1970s, but dominated much of the strip's final two decades (Spike in the 1980s, Rerun in the late 1990s). Even diehard fans had their patience tested by the repetitive gags involving Spike interacting with a cactus. Rerun seems to have caused a Broken Base. Some fans resented him for upstaging the classic characters, others thought that Charles Schulz managed to pull off a successful Rescue from the Scrappy Heap: Before the 1990s, Rerun was almost exclusively known for strips where he rode on the back of his mother's bicycle, and made terrified comments about her absurdly scary cycling skills.