Although I have to ask... if you find an actor for this thread, does it have to be a part they played in a former (earlier) or later film... or TV show?
Whatever, let battle commence... 
Yea, here's the way it should go:
-Shush put the film "
Troy"
-next one should put a film where is/was some actor
who ALSO had a role in Troy; like "
Interview With A Vampire - Brad Pitt"
-then the next one remembers
another actor who had a role in Interview With A Vampire - and put
some other movie where that actor (like Master Ray) had a role (f.e. "The Family Story: Clogs and Bushy Beards On The Move - Master Ray")

You can also choose same actor's another movie if you can't remember/don't know his other films.
Btw, the point about TV series is a good question: if you check Samuel L. Jackson`s page at IMDB you will find out from his portfolio there`s mentioned also series and even computer games where his voice is used with the characters. But you make the choice; if you lead the puzzle to a stage no one can't find "out" a way, it lessens our chance to continue the battle.

- - - - - - -
Ok, please continue from James Cosmo and Trainspotting.