A weekend
Short, brilliant seasons are perfect for a weekend: Chernobyl tells its story in five episodes, The Last of Us and Shōgun each hold a stunning first season, and Squid Game grips from the first minute.
A week
With a week, try Severance, Slow Horses, The Bear or Arcane: a few seasons each, all of them rewarding.
A month
For a month, go big: Breaking Bad and then Better Call Saul, or Game of Thrones and then House of the Dragon, or Stranger Things from the first season to the last.
Forever
The long runs keep going and going: Supernatural, Grey's Anatomy, NCIS and The Simpsons. The Long-Running Series shelf lists them all.