Seriously, how many?
Go to WIKIPEDIA and be told one thing -- actually two things -- the real seasons and how FOX counted them but go to TBS or ADULT SWIM on demand and grasp that there's an entire other system of numbering the seasons.
We're not joking. At ADULT SWIM, the latest season was Season 14 which concluded with episode 20 "The Hand That Rocks The Rogu" which first aired on August 26, 2019 on TBS. WIKIPEDIA agrees with that title and that it was episode 20; however, they argue it was Season 16.
However, you want to count the seasons, it was episode 276 of the series.
Early on, it became clear that Roger needed to be more than the subplot. "Stan Slickers II: The Legend of Ollie's Gold" has a so-so main story about Stan going nuts and Oliver North and Greg and Terry taping everything but the real gold is in the B-story where Roger proves to Klaus that he can be sexually harassed.
Other things that have emerged over the seasons? Roger's best foil is actually Hayley. When they are in opposition to one another, hilarity ensues. Roger also works well with Jeff and, if there's anger and envy involved, with Klaus.
Here's a baker's dozen of the best episodes of AMERICAN DAD.
1) "Julia Rogerts" written by Kathryn Borel
"Is my dick showing? Like Cher's did?" asks Roger while wearing Cher's "If I Could Turn Back Time" outfit. Roger's trying to help Stan fix a problem with Francine but ends up carried off by a tornado to a simpler place where he becomes Julia Roberts in SLEEPING WITH THE ENEMY and falls for Jesse (voiced by Dermot Mulroney). He even has a service rooster, Percy. And a secret tunnel to steal fudge.
2) "Jenny Fromdabloc" written by Laura McCreary
Steve wants to be big man of his group of friends. But Snot's feeling bad so Roger becomes Steve's cousin Jenny who, Steve explains, has never met Snot before because -- "No one's doing the math," Roger tells Steve. Snot becomes a man. Or does he?
3) "A.T. The Abusive Terrestrial" written by Dan Vebber
Roger finds himself trapped in an abusive relationship mirroring so many of his favorite LIFETIME movies like PLEASE KEVIN, NOT IN THE FACE. He fears he'll end up like actress Daphne Zuniga -- on ABC FAMILY! He needs Steve to rescue him.
4) "Roger's Baby" written by Teresa Hsiao
For Jeff to return to human form (don't ask), he has to be birthed and Roger's just the alien to do it. Along the way, only Klaus understands the baby gift a pregnant Roger truly wants while Hayley can do nothing to please Roger. We also get Roger doing Madonna's "Papa Don't Preach."
5) "Stan's Night Out" written by Jim Bernstein
Hayley and Roger go to the mall and argue over who is prettier. Klaus finds a Craig's List posting that leads the two to the food court. "No babies for Roger," may be the funniest line in the episode. The supporting story, involving Stan, is at its best when Francine's attempting to write a song and then, later, at a sushi bar.
6) "The Enlightenment of Raji-Baba" written by Joe Chandler and Nic Wegener
Roger's persona Tasha grows too old for modeling and he's in despair. Hayley knows what will center him and cheer him up: This new yoga place she's going to. Roger quickly takes over the yoga studio and quickly amasses a following that he plans to mass suicide. Tough times for Roger though, in Nirvana with Hayley, he learns Carla and Coach were never a couple on CHEERS.
7) "The Dentist Wife" written by Charlie Suozzi
"Son of a bitch! He barged me!" Francine declares at one point. Roger becomes obsessed with a dentist's wife, Meredith. At first, he tries to join her book club but space camp curriculum did not prepare him for book discussions. So he torches every costume he has and declares he's a nobody before deciding he will become Meredith.
8) "News Glance With Genevieve Vavance" written by Ali Waller
Concerned about Garbage Island, Hayley, always wanting to make a difference, applies for a local public access news show only to learn it's Roger's show. His persona is Genevieve Vavance. And, yes, he might let Hayley do a report on Garbage Island . . . if she stages Steve's kidnapping. Genevieve goes on to accuse Stan and Francine of kidnapping their own son in the desperate bid for ratings gold.
9) "Pride Before The Fall" written by Soren Bowie
Hayley's plan for her and Jeff to live in her bedroom forever as she continues to enroll at her two-year community college forever hit a snag when Roger, tired of living in the attic, wants that bedroom for himself. So Roger becomes student Lacey Krinklehole who starred in her high school's production of PIRATES OF PENZANCE. Roger/Lacey, "The high school newspaper declared it . . . this year's musical." When all of his efforts to get Hayley to graduate fail, Roger kills off Lacey so that the college will give Hayley an automatic A.
10) "A Star Is Reborn" written by Brett Cawley and Robert Maitis
Okay, the main storyline is so-so. But the supporting storyline is hilarious. Hayley deletes some of Roger's BONES episodes off TIVO and his slow turn to her is hilarious. When Steve defends his sister by insisting the quality of BONES has fallen off, Roger does an equally hilarious slow turn to Steve. Then Roger 'crates' them. The BONES and the crating make this episode.
11) "A Boy Named Michael" written by Erik Richter
Greg and Terry are bored and need to adopt another child: 10-year-old Michael from Russia. People often ask us how happy are you that you got to adopt your gorgeous daughter? And the answer is happy . . . -ish," explains Terry. Stand agrees to go to the party celebrating the news only because of the "awesome baton collection" that Greg and Terry have under their bed. Francine pauses a moment and then advises, "Stan, just wash your hands after." The party impresses Roger -- especially Liev Shreiber and his neck scarf. Roger, fearing the Smith family is beneath him, kicks the boy off an airplane mid flight and assumes Michael's identity.
12) "Shallow Vows" written by Rick Wiener and Kenny Schwartz
Roger becomes Jeannie Gold, wedding planner, for Francine and Stan's wedding anniversary. Jeannie is full of advice and more, "This is my emergency wedding kit -- everything you need for last minute snafoos. Needle and thread, band-aids for sore heels, fake hymens for those not so well behaved Middle Eastern brides -- these beauties are packed full of ox blood. Trust me, that bedroom will look like the set of a Wes Craven movie the next morning." And, "Stan, remember the first rule of any wedding is that the bride is always beautiful. The second rule you can read on my website. You have to be 18 to log on. I have some sexy barnyard stuff on there that is not for everyone. I could get in a lot of trouble. If you do decide to check it out, you need to clear your history right away. You may need to uninstall your browser. I'm telling you, scrub that thing clean. If you think you're being too cautious, you're not. They will take us both to jail." In the end, Jennie is destroyed as a wedding planner -- soggy bag of Chips Ahoy and all.
13) "Personal Assistant" written by Jeff Kauffmann
Roger is sick and can't keep his personas going so Stan fills in. Stan does a half-assed job and the personas go nuts. Roger has to become Jeannie Gold to take on Ricky Spanish. Not to be missed.