My one major problem with 'The Babadook' is that it continues Australian cinema's love of the very intrusive music score and cues, which just show up whenever anything is opened, looked at, mentioned, or reacted to.
The worst example of this is 'Patrick', last year's Horrorthon surprise film - the surprise being that I managed to sit through and stay awake throughout it.
Luckily 'The Babadook' was much better, and gives up on the intrusive score early on, replacing it with unsettling noises, knocking, ticking, and making good use of it all.
Being a new film means that pretty much every second website has a review or article about it, most of which are raving about it - so any one of those should convince you to go see it!
And Do! Do go see it.