I can't go a day without making a new thread, it seems.
I was reading the thread about first person vs third and then I thought: have you ever come across a YA novel that used true third-person omniscient narrative POV ("little did he know he'd be dead by Monday")? I can remember only one example, and it is specifically stylized to look like an old novel (and set in the Victorian period): A Series of Unfortunate Events by Lemony Snicket.
But what about contemporary settings? I don't think I've ever seen anything like that in YA. Most of what I come across is written in first person, and when there is third person, it's limited.