This book has it all! Great characters, great magic system and a great story.
First we have the standard fare of an evil tyrannical ruler that must be defeated. But in this case the Lord Ruler is already in power and has been for over 1000 years. I loved the little surprising twist on the identity of the Lord Ruler.
The magic system is based on metal. Allomancers ingest and burn different metals to enhance various physical and mental capabilities. Mistborns can use all the metals while mistings can only use one. Mistings are far more common and go by names based on the metal they can burn. So we have Smokers, Tineyes, Soothers, Coinshots, Thugs (Pewterarms), Seeker, Lurchers. Feruchemists use the same metals as storage devices or batteries (called metalminds) for various physical and mental abilites to be used later.
The characters are very likable. Vin reminds me of Luke Skywalker and Kelsior of Yoda.
Obviously I loved this book and will definitely read the others in the series.