The blog Flashbak takes us way back to the golden age of made-for-TV movies: the late 1970s. Back then, it was possible to attract big stars for widely-watched movies made for broadcast.
Who would have been cast for the major roles in Game of Thrones in 1977? Flashbak is right that Michael Landon (Charles Ingalls on Little House on the Prairie) would have been an excellent Ned Stark. Peter Cushing (Grand Moff Tarkin on Star Wars) would be perfect as Tywin Lannister, as would Ricardo Montalban (Mr. Roarke on Fantasy Island) in the role of Stannis Baratheon.