I would say Kijiji would be best over all, pretty much the standard go to source for almost everyone. Anything else I would consider as optional or additional. As for Facecrack, well I am not on there, nor are most of my friends, and we are not alone as thats more the younger crowd thing, so you are missing a huge group of buyers relying on that.
With Kijiji be prepared for the fake text messages, emails and phone calls. Seems there are some kind of bots or such at work there, last time I got the first fake text within five minutes of posting the ad.
And the ads that really get my attention, list a price, location and have a phone number. Pics are a good plus as well. Often ads without prices or phone numbers I and many I know simply pass them by. I mean if you go to the trouble of listing something, you know what you want for it, put a damm price in the ad!