I enjoyed particularly this article in the Daily Telegraph, which looks at his successful roles - and those which didn't work so well! Reading it you realise quite what a back catalogue of roles the man has, in some really iconic films spreading from the sixties right up through the present decade, with his role in Batman.
The Ipcress File is properly acknowledged as one of his successes, and his capability to embody a character perfectly is reflected by the journalist:
"Caine’s laconic spy Harry Palmer spends the opening two minutes of The Ipcress File (1965) brewing a hot cup of Java from espresso beans freshly ground on camera? Either way, after the film was released, the popularity of real coffee in Britain went through the roof, roughly in line with Caine’s career."Happy Birthday, Sir Harry .... sorry, Sir Michael!