Some good mentions here.
Robert Jordan - Wheel of Time and the spin off books are fantastic.
Brandon Sanderson - If you liked him finishing the above, the previously mentioned Mistborn series must be finished.
Terry Goodkind... wtf... I thought I finished the Sword of Truth series, but just found out he's written more.... gotta go buy.
Adrian Tchaikovsky - Shadows of the Apt - Currently reading these and would highly recommend. Personally up to Warmasters Gate.
I have read a lot of fantasy over the years, but RJ, TG & AT have kept me enthralled for a long time now.
Robin Hobb... well the Farseer books were difficult to read for me... too dark & dreary with little action. IMO she (yes she... Margaret Ogden in reality) redeemed herself when I was compelled to read The Liveship Traders series.
Other authors... David Gemmel, Katherine Kerr, Tad Williams, Terry Brooks (although he seems to write from the same script each book), David Eddings, JRRT and many many more.
Something different?
Try Stephen R Donaldson's - The Chronicles of Thomas Covenant the Unbeliever. Hard to start, but very worth the read.