Glenn Quagmire (seasons 8-17)

Glenn Quagmire is a recurring character in the Fox adult animated comedy series Family Guy. He is the neighbor of the Griffins, who is known for crazing over sex 24/7.

While he was a tolerable character in the first seven seasons, sadly, he has been flanderized since the eighth season.

Bad Qualities

 * 1) He went from a kind of pervy ladies man, to a repulsive sexual predator who knowingly and gleefully shares his numerous STDs with the women he sleeps with (lying about wearing protection if he needs to), making him extremely unsympathetic to the audience despite how many times the show tries to give him sympathetic episodes (his sister being in an abusive relationship, him being tricked into marrying a prostitute, him being trapped in an abusive relationship with a "female Quagmire", etc.)
 * 2) The way he is written nowadays is all over the place, as he only likes women for their bodies rather than personality and he is not only a pervert, but also a child molester too. There are even times where the show portrays him as the cynical straight-man of Peter’s friend group, a role typically reserved by Joe.
 * 3) Sometimes, he is shown to be somewhat of a bad friend to Peter as he can be seen hitting on his wife Lois constantly.
 * 4) Quagmire not only hits on Lois but he has also hit on several other men’s wives too. He tricked Joe into letting him sleep with Bonnie in “April in Quahog”.
 * 5) He abused Brian three times throughout the series; the first scene was when he severely beat up Brian, the second scene being when he broke Brian’s teeth with a lamp (although, the second time was justified since Brian scammed him into buying a run-down lot, despite that Quagmire helped Brian get his teeth repaired in the beginning), and the third time is where he grabs Brian by the neck and bashes his head at the sprinkler, but after that, they soon apologized to each other. However, he has gone back to hating Brian in the season 20 episode “Must Love Dogs”, and it seems they are not on good terms anymore.
 * 6) Speaking of which, he's a massive hypocrite in calling out Brian. It's implied that the real reason he hates Brian is that he's a dog, and Quagmire is a cat person. This has been confirmed true in the episode “Must Love Dogs” as Quagmire admits to the girl he was dating in the episode that he hates dogs.
 * 7) Elaborating on Quagmire’s hypocrisy concerning Brian, Quagmire has not only done a lot of bad things Brian did, but the things done when Quagmire did them are a lot worse than when Brian did them. For example while Brian was revealed to have gathered only one kid and failed to treat him well, Quagmire on the other hand was revealed to have fathered more than six children yet he was never around for them.
 * 8) Because of his hatred for Brian, Quagmire  ends up kickstarting an infamous feud between himself and Brian. That feud has been criticized for being the focus of many episodes to the point where it became annoying and caused both Quagmire and Brian to undergo further character derailment and flanderization.
 * 9) In “Quagmire's Baby”, he names his daughter after a sexual innuendo Anna Lee, and when he gives her up for adoption and sees she happy with her new family, it was a heartwarming way to end the episode, until its ruined when Quagmire said he could meet up with her when she's eighteen and have sex, which is incest.
 * 10) *In "Quagmire & Meg", Quagmire plans to hump Meg when she turns 18, which is not just disgusting, but it also makes him a pedophile in a way, due to the massive 43-year age difference between both of them.
 * 11) **In many episodes, he is just very easily offended. In “Wild Wild West”, he gets angry at Peter just for talking about someone that he doesn’t know, which is a very petty thing to do.
 * 12) He is also a very bad friend to Peter in some episodes. While most of the time this is justified since Peter was mean to him first, in “Family Guy Lite” he traps Peter in a hole without any food or water for days, just because he wanted to get thinner.
 * 13) Just like all other characters in the show, he has become extremely expressionless as the show went on, on earlier seasons he was smiling most of the time and was often squinting his eyes, almost making him look suspicious and dubious (which matched his older personality of a charming pervert), but nowadays he almost never smiles and looks just as dead eyed as all the other characters, which basically sums up his new, bland personality.

Good Qualities

 * 1) Despite hitting on Lois, Quagmire is very loyal to his best friend Peter as he would never try to hurt his feelings by stealing Lois from him.
 * 2) He still cares about his family and friends. For instance, he defended Brenda from her abusive boyfriend Jeffrey. He also saved Brian and Meg from being kidnapped by cats in the episode "Family Cat".
 * 3) He can still be likable in some episodes (even if they are bad) such as in "Brian the Closer".
 * 4) Despite being disrespectful, at least he didn't gloat over the death of Brian in the episode "Life of Brian".
 * 5) He was a much better character in the first seven seasons and despite not fully recovering himself from his flanderization, his character did see a slight improvement in season 18 and 19, mainly due to him being on better terms with Brian in those seasons.
 * 6) While he started to hate Brian again in "Must Love Dogs", it is revealed the real reason why he hates him due to the fact that he hates dogs, which is (surprisingly) understandable.
 * 7) Despite BQ#8 (1), he's one of the few people who doesn't bully Meg. For example, in the episode "A Fistful of Meg", he helped Meg out in her problem with Mental Mike and trained her to become stronger.
 * 8) Seth MacFarlane still does a great job voicing him, making him sound unique.

Trivia

 * His character spawned a lot of memes.