Hi
 
1.The  �39 Clues � is a popular series at the moment - for boys and girls
2.Scott Westerfeld has written 2 of his 3 trilogy books -  �Behemoth � and  �Leviathan �.  They seem to be reasonably high interest. 
 
For the boys who like high adventure, a few authors may include:
3.Gabrielle Lord - Conspiracy 365 series
4.James Patterson - the author of adult thrillers has written some  �young adult � books such as  �Daniel X �.
5. Rick Riordan - as mentioned in a previous reply.
6. Eoin Colfer - the  �Artemis Fowl � series
 
If you �re looking for some humour (you may need to screen the content)-:
7.Paul Jennings
8.Morris Gleitzman
9.Andy Griffiths
10.Roald Dahl 
 
Some of these authors also write adult fiction so you need to be careful in choosing the titles and some may be a little young, depending on students � English and reading levels.
 
Hope it goes well.