I'm a huge fan of adventure and mythological fiction, so:
Rick Riordan (Percy Jackson/Heroes of Olympus, Kane Chronicles)
Anthony Horowitz (Alex Rider)
Jonathan Stroud (Bartimaeus Trilogy)
Ridley Pearson (Kingdom Keepers)
James Dashner (Maze Runner Pentalogy, Mortality Doctrine Trilogy)
Gary Paulsen (Brian's Saga)
Brandon Sanderson (Alcatraz)
Greg Logsted (Alibi Junior High)
Lemony Snicket/Daniel Handler (A Series of Unfortunate Events)
Scott Mebus (Gods of Manhattan Series)
Eoin Colfer (Artemis Fowl)
and probably some more I've forgotten... most of these are in the teen reading levels, however a few like Dashner and Eoin Colfer are YA.
i have a pretty good mix of authors across a a few different levels
i find i have quite a few adult level reads but there will always be those few teenager series that i will buy as soon as i see the newest one just cause i started them when they first came out way back when and they were good reads then when i was at that level and they are still good reads now and by buying them it supports the author so hopefully he keeps writing them and they get others into reading at that level.