If you Love the Hunger Games check out Michael Grant's series about a world gone mad when everyone over the age of 16 disappears and the kids have to try and figure out how to stay alive and how to make the world go back to normal. Read Gone, Hunger, Lies and Plague and you will be HOOKED!!
If you like the Harry Potter series try this edgier, sexier series by Rachel Hawkins. Hex Hall & Demon Glass feature Sophie Mercer and her angst when she meets gorgeous warlock & resident hot guy Archer Cross. Also just released the 3rd book in the series called Spellbound!