Anything by John Le Carre (David John Moore Cornwell).
His first real biggie, The Spy Who Came In From the Cold, was almost tolerable, although the plot suffered from huge holes, and the notion that spies and double and triple agents, who should be professionally suspicious of everything, would prove to be as gullible as Japanese tourists whenever the plot needed an unlikely turn, stretched the limits of the permissible even in fiction. But at least the story moved along in a fairly even way. Everything else he's cranked out since has been tedious drivel. It looks like he stretches everything out until his editor tells him it's long enough, then he ends it in a few pages, with a mass of loose ends big enough to choke the late lamented Linda Lovelace at her enthusiastic best. His characters, intended to be engagingly eccentric, cross the line to childishly annoying, and the side action, with old government papershufflers perpetually bonking the underage office help, makes me suspect that he's angling to be the ghostwriter of ex-Representative Gary Condit's autobiography. Perhaps most irritating is his chronic anti-Americanism, which is really mere resentment - the American spy agencies are invariably portrayed as too rich and too efficient, and not properly obsequious towards their bumbling British colleagues. Cornwell has some baggage here, to be sure, as his own real-life career as a spy for MI6 was cut short by Kim Philby's treason, though it would take a better gymnast than Cornwell to blame the US for that.
The books are complex, but not thoughtful. Cornwell's political views strike me as astonishingly primitive and naive, casting a general pallor of triviality over his stories. He may know spies from real life, but his grasp of politics and history seem rudimentary.
The peculiar thing is that the books seem bad, but not particularly boring, until the reader realizes that he's actually wasting time on such a bad book. Even worse, if he's read other Le Carres, he'll soon notice the nagging feeling that he's read that book before, and will develop the creeping suspicion that it won't get better if he just keeps reading. These effects, I suspect, are because most of the le Carre books are bad in the same way and for the same reasons. Only after that realization does the boredom set in. It's a curious effect.