Since Cherub, The Hunger Games etc are all available in the school library I think its really hard to stem the flow of them reading them. From what I can gather at this 'age' group it is always the goodies who win, its just far more gory or adulty themes. Mild language, even ******** reference, but dipping in I haven't seen anything explicit. For my boy (one of 2 aged 10) who likes this type, he also likes
Chris Ryan, the younger adult books
Anything by Anthony Horowicz
Anything about Zombies for teenagers. I know! Yucky!
When he picks up a new one I do leaf through it, but although not to my taste, I THINK, (note emphasis) that they are ok, if a bit grim.
If you really want milder for him then this boy also enjoys the Gladiator series.
My other boy loves fantasy, and in his own words 'steam punk' (Victorian Sci fi I think). Not anything vampire, but anything that would sit well with a Lord of the Rings Fan. He is also 10 and actually loves Tolkein, including the Silmarillion, then The Inheritance Series (all big thick ones with a dragon on front cover), anything by Chriss Riddel, The Wizard of Earthsea (thats from the 70s), Wereworld series, and loads more if you are interested. I can supply authors too then, these are off top of my head.
Both enjoyed Lemony Snicket Series of Unfortunate Events, very dark, but plenty of them and age appropriate. Also Harry Potter of course.