The premise was simple: Cleveland and Cleveland Junior (reworked as an overweight nerd since he was last seen way back in the early days of Family Guy) hit the road so that Cleveland can pursue his lifelong dream of being a baseball scout. They opt to make a stopover in his old home town of Stoolbend, Virginia, and by chance run into Donna Tubbs - his onetime best friend from high school and great unrequited love. As it happens, Donna has fallen on hard times, having been abandoned by her no-good ex-husband Robert to raise their kids (teenage Roberta and baby Rallo) on her own. To the surprise of nobody, Cleveland opts to confess his (unchanged) true feelings for Donna, and their blended family becomes the foundation of the new series.
Sitcoms tend to live and die by a strong supporting cast, and if there's an immediate knock against Cleveland it's that there's a lot of what looks like one-joke gimmickry going on in that area: Roberta, the "sassy" promiscuous teen daughter (with a white-rapper boyfriend named Federline, no less); Holt, the fitness-obsessed "bro" dwarf; Redneck Lester Crinklesack and his obese rascal-riding wife; and Tim, a bear who wears clothes and otherwise acts like a human except when he isn't. These guys sound like they'd get old fast, to put it mildly.
But the strength of the Cleveland Show was to take seemingly weak characters (to be blunt: Cleveland Brown wasn't exactly the deepest cut on Family Guy,) and stick with them until they became likable. Well... mostly likable. Tim was bizarre enough to be endearing, Jason Sudekis' delivery eventually made Holt a welcome presence, Roberta got to reveal hidden depths whenever the plot turned to the subject of her education (she's actually a good student and a party-girl) or complicated relationship with her biological father. It was really only Lester who never grew much beyond the meta-joke of being a white redneck voiced by a black actor (Kevin Michael Richardson, who also does Cleveland Junior and American Dad's Principal Lewis) opposite Cleveland (Mike Henry is white.)
But when operating as a unit (or units), this ensemble was capable of solid comedy. Not necessarily ground-breaking stuff (there's a Camping Episode, more than a few Get Rich Quick schemes, a Let's Trick The Wives episode, etc) but the Friends Having Fun vibe feels real. Still, it was the family-centric episodes where the show really shined.
Most shows about what The Simpsons family dubbed "The Post-Nuclear Family" tend to skew heavy in the directions of horrifying dysfunction (Dads, Titus) or quirky sentimentality (Bob's Burgers) favoring a worldview that either plants it's flag in "Life sucks, but here's our shelter" or in "We're nuts, but this works, so yay!" Cleveland was a bit more nuanced, in the vein of the early good seasons of Roseanne, when it came to the facts of what turn out to be two quietly damaged people (Cleveland and Donna both come from abusive homes, his physical, hers emotional) trying to fit two broken families into a whole. Thanksgiving and Christmas episodes strike real nerves in between the broader "raucus southern Black family hijinks" gags, as did "The Me In Me" - which opens with then-topical gags about Cleveland being a Justin Bieber fan and morphs into an introspective journey wherein Cleveland digs into troubled parts of his past after being named "The Whitest Man in America" by local DJs.