The Self-Righteous Brothers were based on a neighbour of Enfield's who also referred to celebrities by their surnames and spoke about them authoritatively as though his opinion was of immense importance, for example telling him "I'd mend your fence, Enfield, but not your mate Elton's, he's a prick."
Modern Dad was based on Enfield's own father.
Tim Nice-But-Dim was also based on several people from Enfield's own life; public schoolboys he knew who were ... well, nice but dim.
Enfield claims that Harry and Lulu were based on a young Lily Allen and her brother, whose mother he was dating at the time.
Stavros was based on a kebab shop owner Enfield knew.