Joseph Ruskin
From Memory Alpha, the free Star Trek reference
(written from a Production point of view)
Hailing from Haverhill, Massachusetts, Joseph Ruskin (born 14 April 1924; age 85) has appeared in every Star Trek series except Star Trek: The Next Generation (though he did appear in a Next Generation feature film). With the exception of Majel Barrett, who has appeared in every "Star Trek" series, he is the only actor to appear in all four of the series in question. He has had a long and distinguished career, appearing in TV shows as early as 1959. More recently, he had a recurring role as "Alliance Member Alain Christophe" in J.J. Abrams's TV series Alias, as well as playing an elderly mob boss in Smokin' Aces, which featured Chris Pine.
Along with Majel Barrett, Clint Howard and Jack Donner, he is one of only four actors to appear in both Star Trek: The Original Series and Star Trek: Enterprise. He, Barrett and Howard also appeared in Star Trek: Deep Space Nine.
