Although Anthony Franciosa starred in four TV series (accoprding to the Internet Movie Database, he was on the short-lived 1972/73 cult favorite "Search" as well as "Valentine's Day" , "The Name Of The Game", and "Matt Helm") and appeared in quite a few movies and TV guest shots, I would think most people who remember him will remember his being on "The Name Of The Game".
Franciosa's character on that show was investigate reporter Jeff Dillon.
Because the show was 90 minutes long, it was actually three series in one; with three stars who would be seen every third week. The others were Robert Stack (as magazine editor Dan Farrell) and Gene Barry (as Glenn Howard, the owner of the company that Stack's and Franciosa's characters worked for).
"The Name Of The Game" was based on a 1966 TV-movie "Fame Is The Name Of The Game", which starred Franciosa in the role he would later reprise in the series. The character of Glenn Howard was also in the TV-movie, but was played by George Macready. Macready also played Martin Peyton on "Peyton Place" at the time, and was thus unavailable to play Glenn Howard in the TV series, so Gene Barry stepped-in.
"Fame Is The Name Of The Game" was one of the earliest made-for-TV movies, and was the highest-rated made-for-TV movie up to that time. It's enormous success led to NBC's decision to turn it a series in 1968.