Brandon Sanderson has a LOT of fantasy books out, but the series I first encountered (and that Sanderson first became really well known for) is the Mistborn series.
The Mistborn books are fast paced and action packed. The first trilogy (more on that in a second) follows Vin, a street urchin revealed to be one of the mistborn: Magical warriors capable of "burning" metals in their stomachs to temporarily acquire various powers. Pewter makes them stronger and more resilient. Tin enhances the senses. Iron and steel allow mistborn to push and pull on metal, which makes for some truly epic battles, as mistborn fly through the streets by pushing off (and pulling towards) metal. It often feels pretty wuxia flavored, in the best possible way.
Vin quickly gets caught up in a rebellion against the Lord Ruler, the immortal tyrant of the Final Empire. I won't spoil the rest of the series, but that's just the stakes of the first book- the later books in the first trilogy get much, much higher stakes.
I keep mentioning the first trilogy- that's because Sanderson does something fantastic with Mistborn. There's a second Mistborn series set centuries later, when technology has advanced to a point equivalent to the Wild West. It follows a former lawman, Wax, as he sets out to solve a series of kidnappings in the capital city while trying to rebuild his family's fortunes. I can't say too much about this series without spoiling a lot of things, but it's freaking awesome. Also, magical gunfights are absolutely amazing.
If that weren't enough, two more Mistborn series are planned- one set at a technological level equivalent to our own, and one set at a scifi level of technology. I can't wait for either.
