The Runaways probably is more children's, although some of the subject matter is more YA. The other three are all 2009 launches (The Hunger Games came out in the US in 2008, but this is the UK launch), with fairly big promotional campaigns, and they're all series, which is a tendency I would, personally, like to discourage. I like The Demon's Lexicon best of the three, but even there it's going to be interesting to see if there's enough for a trilogy.
RJ Anderson, Knife. An all female tribe of fairies who reproduce via reincarnation live a fading and precarious existence in an oak near a house where the newly paralysed son of the owners broods moodily. I like Knife's blunt effectiveness, and the fact that she does make mistakes; against that, tho', is the huge amount of time it takes to get the story started, and the fact that the progression of the story relies on finding ancient diaries that reveal the story.
I am unkeen on this trope at the best of times - it always annoys me that these things are always found in chronological order, for a start - but it is possible for a story relying on uncovering the past to work for me, if - and it's an irritatingly rare if - there is also adequate forward tension in the non-retrospective parts of the story. Old Boy, a manga I've just finished reading, is excellent at making attempts to identify past events generate new lines of tension in the present, or Stephen King's It if you want print references. Knife has a romance, instead, and maybe it's personal preference, but there wasn't enough there to keep my interest. I do like the way fairies become muses, of sorts, and I like the fairies' attitude to gratitude and personal debt, but I'm not all that thrilled by Paul, and I never managed to adequately block Knife's size (which, to be fair, does change).
Suzanne Collins, Hunger Games. Comes complete with an enthusiastic quote from Stephanie Meyer (on both the front and the spine - same quote). Katniss, poor but smart, brave and prone to dangerous idealism, ends up in the Hunger Games, a televised event in which two representatives from each of twelve districts in a post-semi-apocalyptic America fight until there is only one winner left alive. Battle Royale with less intra-class tension and more media intervention/manipulation, basically (and fewer panty shots, which - along with random homophobia/transphobia and the quality of the translation - is why I've stalled out at about v5 of the manga).
What I liked about this is the pace, and the manipulation aspects - the way Katniss' image is engineered, and the way she starts doing it herself, because getting audience sympathy can get you medical aid or food dropped in from helicopters. What I disliked was the development of the central idea, because the idea of teenagers forced to kill each other for the entertainment of others gets undermined in order to force sympathy for the "good" characters. Firstly, there are Career Tributes - people trained specifically for the Games, who volunteer - thugs, basically, who can kill off all the unimportant other Tributes and then act as an evil, undeveloped opposition. Then, how Katniss actually competes; I was thinking absently as I read that such a book couldn't possibly have the narrator kill another teen outright first-up, that her first attack would have to be something like an avalanche, so that any deaths could be blamed on their inability to escape in time, and then there's the kill someone to save a third party, and then killing someone to stop them being in unbearable agony, all situations that don’t make your character look too ethically dubious… and it all happened. I'd been hoping for some sort of twist or moral ambiguity, but no. To cite two Stephen King works in one post - this fails to follow through to the bitter implications of its premise in the way that The Long Walk did.
Sarah Rees Brennan, The demon's lexicon. This did not remind me of any Stephen King books. Instead, it's fast, dark and funny, with well-established characters, an interesting magic system and a swift trot round bits of the UK not all that commonly explored in fantasy fiction (like Exeter). I enjoyed it a lot, and it's only unfortunate that, in the climatic sequence, where two brothers are desperately trying to defend each other, and one of them is trapped in a magical circle, that I suddenly had massive Full Metal Alchemist flashbacks and ended up finding the end of The Demon's Lexicon rather anaemic by comparison (I think this is also not helped by the fact that Hiromu Arakawa did the Japanese cover for this book. At least it wasn't Stephen King). Apart from that, the author is a little too fond of witty cool good-looking bad guys who will turn out to be redeemable (disclaimer: I have read a not inconsiderable portion of this author's fan fiction), but, on the bright side, this is one of the few YAs I've read this year that actually gets in and starts the story at exactly the right place, without fluffing around with endless backstory.
Zilpha Keatley Snyder, The runaways. Dani lives in the middle of the desert (US) with her mother and hates it; she wants to go back to California, but her mother can't afford the move. Dani begins saving to run away, but Stormy, a young boy who follows her around and comes from an even more miserable background, wants to come too, and then a new, strange, girl moves into town… This is a good solid story, and although the big reveal is predictable enough, there are a lot of nice character moments and smaller twists along the way that aren't. Nice portrayal of a small town community, and the tensions there, and the connections and disconnections between adults and children - who knows what, what power they have, and what they'll do with it.