Well, apologies for silting up the Chappaquiddick thread but I can't resist the RI movie angle vying for recognition herein.
Iamwhomiam: I haven't seen 
The Magic Christian but it sounds like another great vehicle for the elevated comedic brain of Sellers.  Two others of his are in my all time great 'RI themed' movies.  
Dr Strangelove and that grossly underrated parable about the irrelevancy of the office of the chief executive - 
Being There.  In the title role of Strangelove, I love the Seller's nazi salute schtick, which is an allusion to photos of Werner Von Braun's capture during WWII.  The photos show von Braun wearing a massive plaster cast on his arm keeping it outstretched as if in perpetual 'heil'.  I often wondered about those photos, such a huge plaster cast.
Elvis: Of all the Hitchcock movies 
Saboteur is an interesting one to select.  Love that era though - two of my faves from around then would be 
Citizen Kane and 
The Third Man.
Joe: On amazon copies of 
Twighlights Last Gleaming sell for a lot so it must be good. Do you know of an Australian movie called 
The Cars That Ate Paris? It's supposed to be a cult classic.  
MinM: Burt Lancaster's parapolitical big four!  I'd add 
Birdman of Alcatraz and 
Elmer Gantry (as a minimum) into a complete RI themed Burt Lancaster list and offer it up to whoever it is that passes judgement on such things because it seems to me he should be given a lifetime of achievement award for acting RI themed roles.  Matter of fact I'm confidant Burt would have been a RI member. 
http://www.angelfire.com/oh2/writer/burtlancaster.htmlstoneonstone: BBC mini-series? Well you've opened Pandoras Box there.  On your recommendation then I'll check out Edge of Darkness.  I think I take a counter view to yours regarding Executive Action vs Condor though.   
bardobailey: You'll get no argument from me on 
Manchurian Candidate & 
North by Northwest. Candidly, and as always I can only speak for myself here folks, I don't think I could resist the wiles of Eva Marie Saint either. In fact, it would appear churlish to even try.
JackRiddler: Yep right on the money re the comment on Tinker Tailor Soldier Spy.  I found the recent Gary Oldman movie re-make dreadful in comparison!  And although Oldman was fantastic as Smilley and Colin Firth was great as Haydon - but changing the story-line??  I was doubly surprised to see that Le Carre was listed as an EP in the credits and therefore we have to assume that he was 'OK with the changes'. All I could think of was that sales of his new book, Our Kind of Traitor, must be down.  The TTSS mini-series with Sir Alec Guiness is amazingly good ranks highly along with, I Claudius.  The Brits do dialog like nobody else can. Officionados of the spy genre say that few can paint that espionage atmosphere in words like Le Carre can.  I think that the mini-series succeeds in conveying those dark atmospherics.
 
			I know of no safe depository of the ultimate powers of society but the people themselves
- Thomas Jefferson