It is truly an extraordinary achievement for a sitcom to maintain high quality over multiple seasons. Producing a half-hour comedy show presents a challenging process even for the brightest writing and acting teams; during this process, it is essential to create both independent stories and to be genuinely funny. While some sitcoms progress successfully until their second season, others start strong but decline over time. However, a few shows make a strong start and end on a high note. Here are 10 sitcoms that are perfect every season.

NBC's 30 Rock focuses on the effort to produce a lively sketch comedy series. Tina Fey stars as Liz Lemon, the head writer of a fictional sketch show, whose life is turned upside down by the new NBC executive Jack Donaghy (Alec Baldwin). Jack's first move is to add controversial comedian Tracy Jordan (Tracey Morgan) to the show; Liz initially dislikes this situation, but her opinion changes when she sees the results.

30 Rock episodes progressed relentlessly, filling every moment with clever jokes. Despite frequently facing cancellation threats, the show had a passionate audience that remembered every inside joke or rare reference. The humor of 30 Rock was unafraid of being quirky or specific to a certain niche group, and that spirit continued until the series finale.

The Frasier series, while a spin-off of the beloved Cheers, managed to make viewers forget about Boston thanks to its writing and acting quality. The show revolves around Dr. Frasier Crane (Kelsey Grammer) returning from Boston to Seattle to host a radio call-in show. When his father Martin (John Mahoney) is injured, the two men quickly come together, and Frasier reluctantly accepts him as his roommate.

It is quite surprising that Frasier produces entertaining episodes filled with complex comedic mishaps reminiscent of mini stage plays. With a different style and tone from Cheers, Frasier avoided comparisons and offered the opportunity to explore Dr. Crane from new perspectives. Grammer knew his character very well before the spin-off began, but characters like his disciplined brother Niles (David Hyde Pierce) or blue-collar father Martin brought new dynamics to Frasier.