You didn't offer enough choices. I would like no movies. Zero. Zip. Zilch. Nada.
Instead, I'd like a TV series, because I figure even a single (US "standard") season of 20-24 episodes would allow for a much, much better adaptation than would be likely even with multiple movies. And ideally two or three seasons would allow at least, say, 6 episodes for each of the earlier, thinner books, and 12 episodes each for the later books.
I'd rather a quality adaptation (movie or TV) of just the first book than a low-budget rushed dodgy cardboard-set version of all. Not that a huge budget would be necessary, because there are no giant explosions, spaceships or Matrix-style freeway car-chases to include.
But I don't see a TV series happening, not even as 6-episode mini-series, and I don't really see a movie happening either, so I just went ahead and voted "12" as the wishful-thinking option.