American Dad is Seth MacFarlane's second cartoon, and it aired on Fox before transferring to TBS in 2014. MacFarlane and co-creator Matt Weitzman were inspired to create the series following their frustrations with the Bush Administration. The basis of the show is Stan's conservative beliefs conflicting with his daughter Hayley's liberal views. The series' format is similar to Macfarlane's other show Family Guy. However, it distinguished itself by being more character-driven and having its distinctive brand of humor.
These two factors have been integral to the series' success. The characters, especially, give the show its signature personality and make up some of Fox's most memorable animated characters, with the ten listed below being American Dad's best.
Barry Robinson
Barry is one of Steve's best friends and is usually the butt of the joke. Others, including Stan, tend to poke fun at his weight and intellect. However, what most do not know is Barry is a criminal genius and a force to be reckoned with, but only when he doesn't take his medicine. Generally, Barry is an easy-going kid who sporadically shines with his obtuse comments and actions. He is voiced by Eddie Kaye Thomas (American Pie).
Jeff Smith nee Fischer
Jeff started as Hayley's boyfriend before becoming her husband. Stan initially loathed Jeff because he saw him as nothing more than an oafish stoner. However, after witnessing his loyalty to Hayley and the family, he gradually warmed up to him and considers Jeff part of the family. Jeff was based on Macfarlane's friend of the same name and is even voiced by him.
Klaus Heisler
Klaus was an accomplished Olympic skier before having his brainwaves switched with a goldfish by the CIA. He has lived with the Smith family for years and is often treated as a pet despite having a human conscious.
Out of the entire family, he is picked on the most. While the Smiths usually do not take him seriously, there have been occasions where he threatened them to such a severe degree they got paranoid. Klaus is voiced by Dee Bradley Baker (Star Wars)
Deputy Director Bullock
Stan's boss and the head of the CIA, Bullock started as a formal character, but, as the series progressed, he became more eccentric and lewd. Bullock tends to get Stan wrapped up in his life, and vice versa, including when he briefly dated Hayley.
He is also shown to be incredibly unhinged, especially when abusing substances. McFarlane specifically had Patrick Stewart in mind to voice the character, being a fan of Star Trek: The Next Generation, and the actor was pleased to do it.
Hayley Smith
The only daughter of Stan and Francine Smith, Stan and Hayley had a close relationship during her youth, but as she developed her personality and ideals they stayed further and further away.
She is passionate about her beliefs and is driven to help make the world a better place, but, as a result, tends to butt-in and comes off as preachy. She is usually seen as the voice of reason, though her motives aren't always pure. She is voiced by Rachael MacFarlane (The Grim Adventures of Billy and Mandy).
Principal Lewis
Lewis is Steve's transgressive and philandering Principal. While Lewis was more somber in his debut, he still displayed a chaotic tinge. One of the jokes in the series was Lewis having this formal position while also being a criminal and bad influence among the students and staff. He tends to collaborate with Steve or Roger and usually ends up in legal trouble. Kevin Michael Richardson (F is for Family) voices Lewis and shares a resemblance with his character.
Francine Smith
The matriarch of the family, Francine was established early on as a former party girl who gave up her lifestyle to become a housewife. However, her past mindset and habits have managed to stick with her, as was evidenced when she helped Stan get into a soldout concert or helped Steve impress the popular kids. While she can act aloof towards her family, she has their best interests at heart and has gone to hell and back for them. Wendy Schaal (The Burbs) voices Francine.
Stan Smith
Stan is the patriarch of the family. As a CIA agent, he is more or less incompetent, with his actions sometimes resulting in the deaths of his colleagues and or the mission is jeopardized.
The same goes for his parenting. Stan tends to get caught up in his narcissism, which sometimes causes him to neglect his family and responsibilities. His rash decisions and actions usually result in negative but hilarious consequences. Ultimately, he wants to do his family and country proud. Seth MacFarlane voices him.
Steve Smith
The youngest and only son of the Smith family, Steve is a precocious high-schooler who is determined to get some action with the ladies and geek his nerdy heart out. Despite being book smart, he tends to be short-sighted and naive, including when he mistook a crackhouse for Hogwarts. Steve is also proven to be virtuoso and an exceptional vocalist. His voice actor Scott Grimes (The Orville) is an accomplished singer as well.
Roger Smith
Roger was taken in by the Smith family after he broke out of Area 51 and rescued Stan. Being a social creature, he wears various disguises outside of the house to hide his alien identity and mingle with humans. His disguises have taken on a life of their own, with some even disassociating with Roger.
He is notorious for his outrageous behavior and has committed a litany of crimes. He is beloved by the family, and he loves them back. Roger is voiced by Seth MacFarlane, who based his voice and mannerisms on Paul Lynde.