First Date - S5-E20
Continuity mistake: Frasier and Niles are in the kitchen while Daphne is getting some fabric softener - Niles is holding a blue bottle of water up near his chest but in the next shot it is down by his waist.
First Date - S5-E20
Continuity mistake: While they are in the living room, Niles is telling Frasier about Phyllis, and he has his bottle of water in his left hand but as the shot changes and Frasier says "Oh, good lord", the bottle switches to Niles' right hand.
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.