fastidious

fastidious \fa-STID-ee-uhs\, adjective:
hard to please; extremely refined or critical
For months, his tall, fastidious figure had prowled around the old city hall on Wall Street, examining its eighty-year-old brickwork, muttering to himself in French, or his syntactically challenged English, imagining-where others saw merely a tired old workhorse of a building-a blank canvas upon which to paint an architectural epic.
-- Fergus M. Bordewich, The Making of the American Capital, 2008-05-16
Penske cannot say for sure that being fastidious off the racetrack results in being fast on it. What he can say, though, is that he has created a culture that has fostered loyalty.
-- Dave Caldwell, New York Times, 2006-05-28
c 1440, "full of pride," from Latin fastidiosus "disdainful, squeamish, exacting," from fastidium "loathing," most likely from fastu-taidiom, a compound of fastus "contempt, arrogance" and tædium "aversion, disgust." The meaning "squeamish, over-nice" emerged in England by 1612