The beginning of the end. While Two and a Half Men had spent nearly a decade atop the list of most popular comedies on television, audiences will remember well that season 8 is when Charlie Sheen had his meltdown and derailed the entire series.
The eighth season was meant to have the ordinary 22-24 episodes that a typical sitcom produces, but Sheen's off-screen problems caused production to halt roughly 3/4th of the way through the season - as it would turn out, Sheen would never again return to the beach house in Malibu. That said, before the end came, season eight still did its best to produce as many laughs as the show always had.
The Immortal Mr. Billy Joel, Episode 5 (7.8)
While Charlie is out of town on a gambling trip, Alan finds some money in Charlie's nightstand and decides to pretend to be his wealthy older brother for the night. Unfortunately, he runs into a girl at a bar whom he brings back to the beach house - only for her to reveal that she's been with Charlie and knows that he isn't who he's claiming.
He tells her the truth and they get past it (because she likes role-playing) but things take a turn when she gets Alan into bed and she comes out dressed like a Nazi - turns out it wasn't a deal-breaker.
The Crazy-B**** Gazette, Episode 7 (7.9)
Rose had quite a few schemes that she pulled over the years where she tried to trick Charlie into falling in love with her, but this might be the one to take the cake. Charlie's crazy stalker comes by to tell Charlie and Alan that she's getting married.
Charlie doesn't believe her and knows it's just another scheme - only to pull up to the church on the wedding day and look through the window to see Rose actually getting married. But, of course, once Charlie walks away and realizes that he's always loved Rose, the camera cuts back to the church where it's revealed that everyone besides Rose is just a mannequin.
Springtime on a Stick, Episode 8 (7.9)
The two titular brothers made it known from the very first season that they weren't fond of their mother, which is why they weren't thrilled when Evelyn was convinced to spend her birthday at the beach house with her sons (thanks to Jake).
Not wanting to be left alone with their mother, Charlie and Alan try to set her up with their pharmacist, Russel... except the idiot didn't know it was fix-up and showed up to Evelyn's birthday party with his own date. However, in a twist of events, Evelyn and Russel's date wound up in the shower together so it ended up being a happy birthday for Evelyn after all.
A Pudding-Filled Cactus, Episode 3 (8.0)
Despite Alan finally finding Lyndsey, a woman who seemed like a good fit for him (and had invited him to move into her house), Alan decided to keep sleeping with his old receptionist, Melissa. Charlie, keen on getting his brother out of his house once and for all, tells Alan he has to pick one of the girls and make a decision.
Alan chooses Lyndsey, breaks things off with Melissa, and Charlie finally gets his house to himself - that is, until Alan accidentally burns Lyndsey's house down on the first night that he's there.
A Bottle of Wine and a Jackhammer, Episode 2 (8.1)
In the episode before Alan moved in with Lyndsey and burned her house down, he had to get invited to live there in the first place. She does so in this episode, simultaneously telling Alan that she loves him, and Alan doesn't exactly reciprocate in kind. He mulls the situation over but admits that he's comfortable living at the Malibu beach house and doesn't want to leave.
Too bad for Alan, Charlie immediately does everything he can to make Alan 'uncomfortable' so that it will drive Alan out. Alan eventually does decide to leave, but right before he moves to Lyndsey's he runs into his old girlfriend, Melissa, and the two rekindle their flame.
Hookers, Hookers, Hookers, Episode 4 (8.1)
After Alan burned down Lyndsey's house, he obviously had to move back in with Charlie - as did Jake, Lyndsey, and her son, Eldridge. The now cramped house makes Charlie miserable and rather than spend time in his own home, he decides to hang out alone in the charred-remains of Lyndsey's house.
While there he runs into Chris McElroy (Lyndsey's ex-husband) as well as Herb and Gordon. Alan eventually joins them and the five men get drunk off a bottle of liquor - only for Lyndsey to show up to drive Alan home and wind up leaving with her ex-husband, leaving Alan alone in the blackened rubble.
Twanging Your Magic Clanger, Episode 6 (8.1)
Charlie and Chelsea had been broken up for a while at this point but Charlie was just getting himself back into the dating pool. His first true date was with a dermatologist whom he thought was only 36 years old but found out on their date that she was actually 47.
At first, Charlie is freaked about dating a woman older than him but comes to terms with it when he realizes how great the woman is - only to face a completely different problem when the woman turns out to have a gorgeous 20-year-old daughter.
A Good Time in Central Africa, Episode 9 (8.1)
Berta always made it clear that she was in charge of the household, which meant that she was rather lackluster in her housekeeping skills. When she leaves for a family reunion and has a fellow housekeeper fill in for her, Charlie and Alan quickly get spoiled by the new housekeeper, Esmerelda, who does dozens of things that Berta won't (and does them better).
Once Berta comes back to work, Charlie misses Esmerelda so much that he has her come in behind Berta's back - which she finds out about and threatens to quit, causing Charlie to ultimately choose Berta.
Three Hookers and a Philly Cheese-Steak, Episode 15 (8.2)
Alan decided to open this episode by asking his brother for $5000 to invest in his chiropractic company, and Charlie gave it to him so easily that he began asking all of his family and friends if they'd like to invest as well - which they do. Unfortunately, Alan winds up with so much money at once that he starts spending it on himself instead.
When people start to notice this, he begins a Ponzi scheme where he takes the "invested money" and claims that it's profit with interest included, prompting all the investors to invest even more and more money. Alan ends the episode by tossing the countless amount of cash he's stolen from his friends/family around on his bed.
Three Girls and a Guy Named Bud, Episode 1 (8.6)
It was clear from the first few seasons that Jake (while still being Alan's son) was definitely more like Charlie than he was his father, and he proved it during the season opener when Charlie and Alan caught two girls sneaking out of Jake's room.
Jake claims the girls are just friends and nothing happened (making Alan happy) but Charlie catches them sneaking out of Judith's house later in the episode and realizes that they aren't "just friends" (which makes Charlie happy).