Continuity mistake: Just after Niles has run out of Cafe Nervosa, the tip he left on the table keeps vanishing and reappearing between shots.
Continuity mistake: When Niles and Frasier are first talking to one another in Cafe Nervosa, Niles' coffee cup goes from held in his hand to sat on his saucer in an instant.
Answer: It equals the record of James Arness of "Gunsmoke" for the actor who's played the same part on TV NOT in a soap opera. If you include soaps there are two main contenders - William Roache, who's been playing Ken Barlow in "Coronation Street" in the UK since 1960. Don Hastings has been playing Robert Hughes in US soap "As the World Turns" since 1960 as well.