Is there a long standing sitcom that introduced a recast/new main character that was well received?

Submitted ⁨⁨2⁩ ⁨months⁩ ago⁩ by ⁨bOt@zerobytes.monster⁩ to ⁨television@zerobytes.monster⁩

https://www.reddit.com/r/television/comments/1vjfnvg/is_there_a_long_standing_sitcom_that_introduced_a/