- Season 15: Er

The two-hour series finale, , is frequently hailed as a masterclass in how to end a long-running drama. Reviewers from IndieLondon gave the season a 5 out of 5 rating , noting that it successfully tied up loose ends for current characters while giving past favorites a meaningful "cherished" send-off.

: The standout feature of this season is the return of original cast members. Fans were particularly moved by the guest appearances of icons like George Clooney (Doug Ross), Julianna Margulies (Carol Hathaway), and Anthony Edwards (Mark Greene), whose flashback episode, "Heal Thyself," is cited by viewers on Reddit as one of the series' best. ER - Season 15

While some viewers initially felt the show had lost its way in its later years, Season 15 is largely seen as a return to form—reclaiming its status as one of the best medical dramas in television history. The two-hour series finale, , is frequently hailed