I will have to agree with Maria_Merriweather. David's first meeting with Barnabas was powerful and realistic. Watching that episode at the 2001 Paley salute to DS was the first moment I realized just how talented an actor David Henesy really was. By the point in the show that was airing on Sci-Fi at the time (just after this horrendous Summer of 1970, as a matter of fact), David's scripts had so degenerated that most of his lines consisted of, "Aunt Elizabeth/Maggie/Mrs. Johnson, I'm frightened/hungry/not sleepy." These were formulaic scenes and dull to watch, but with a glimpse of the early episodes, I finally realized that Henesy the actor wasn't to blame and that with a good script he could really shine! Indeed, he was a veritable lighthouse in the pre-Barnabas episodes as the semi-psychotic-but-slowly-thawing David.
I always felt that Henesy had great chemistry with Mitchell Ryan. David Collins was almost human when he was around his pal, Burke Devlin. Their friendship was one of the healthiest on the show and it was a joy to watch all of their scenes together.
Of course, any time that Henesy got to play possessed was gold!
ProfStokes