The Worricker Trilogy (Page Eight / Turks & Caicos / Salting the Battlefield) [DVD] 
Probably best not to say to much about the plot, a senior intelligence analyst played by Bill Nighy locks horns with a Blair like PM played by Ralph Fiennes, over a series of three feature film length episodes.
This has all the hallmarks of a quality drama, top notch actors, intelligent script, plenty of location shooting. For me, the first episode was engaging, the second with its tropical island setting was less predictable and more interesting because of it. In the last film, Nighy is pretty much sidelined, as the plot unfolds with a certain cosy inevitability.
As with Tinker Tailor, this is largely populated by public school types, but this time women predominate to good effect. It is not the edgiest spy story ever, at no point does Bill Nighy ever risk getting a good kicking from someone, or even a particularly stern word. At heart this is about public school types, with privileged lives, annoyed about offscreen human rights abuses. Within those constraints it is difficult to see how it could have been any better made, the question is more whether this is the sort of things that you want to watch and rewatch. Personally I really enjoyed it, but cannot see myself rewatching it.