I have a hard time picking now, and Houle used to be a runaway #1 here.
It's hard to separate my feelings about the two, as well. Houle was in over his head from day #1 and everyone pretty well knew it. Plus it seemed fairly obvious that Ron Corey / Molson were pinching pennies and there was a move afoot to run the team on the cheap. So it's hard to hold Houle completely at fault for his tenure. He also remained fairly humble through the role. You honestly just felt kind of bad for him that he got shoved into that seat.
Bergevin, on the other hand, has full confidence from ownership (why, we've no idea), no effective budgetary limits (though who can tell), is obscenely arrogant, routinely throws players both current and just-traded-former, under the bus, loses major trade after major trade through no fault but his own, and stuffed the organization full of cronies & yes-men, several of whom he's now sacrificed to try saving his own skin.
I guess it's a hair-splitter between ignorant incompetentence and arrogant self-righteous incompetence. You can maybe, just maybe, educate the former, but the latter is a hopeless project who should be terminated with prejudice as soon as humanly possible.