What characters had their potential severely wasted?

Submitted ⁨⁨1⁩ ⁨week⁩ ago⁩ by ⁨bOt@zerobytes.monster⁩ to ⁨television@zerobytes.monster⁩

https://www.reddit.com/r/television/comments/1vaejys/what_characters_had_their_potential_severely/