Mistborn by Brandon Sanderson is a great novel set in the world of the Final Empire, where Ashmounts belch dark ash across the land and a red sun beats down upon sickly brown foliage.  In the Final Empire, there are basically two classes of people: Nobility, and Skaa.  The Skaa are slave workers, to be beaten, mistreated, and killed on a whim.  Although the Nobility believe otherwise, the Skaa don't much like it.

This is a story about the Skaa rebellion, and specifically the roles of two unlikely characters within it.  Vin, who is a street urchin working for small time thieving crews to scrape a little food and hopefully avoid another beating, and Kelsier, a flamboyant agitator whose ego seems to eclipse any other concerns.

In this world there is a magic known as Allomancy.  Allomancers can "burn" a metal they had ingested for some effect.  For example, burning pewter will enhance an allomancer's strength and endurance.  All metals have a paired opposite.  Bronze detects allomancy, while copper shields it.  Unfortunately, most allomancers can only burn a single metal.  Which metal they can burn determines what type of allomancer they are.  Thug, Tineye, Smoker, Soother, Coinshot, etc.

On the rare occasion, however, some folks can burn all the metals.  These are known as "Mistborn".  Being able to use every metal is a huge advantage, and such individuals can often tackle a squad of allomancers and win.  Kelsier happens to be such an individual, and he's had enough.

To topple the Final Empire, however, one would have to defeat the Lord Ruler.  He is the immortal god-like leader of the Final Empire, centuries old and unstoppable.  Further more, he is defended by Inquisitors, which make Mistborn seem like amateurs.  And finally, he controls the atium supply in the empire.  Atium is a special metal which lets the user see a second or two ahead in time.  This puts anyone without atium at an impossible disadvantage in a fight.

It's a rich world of interesting details, and the characters are all very engaging.  The POV is kept limited to just a few characters, so you don't suffer from information overload.  You basically learn about the world as Vin does, which is refreshing after reading any Malazan novel.