I'm hugely addicted to the Malazan series by Steven Erikson and Ian Cameron Esslemont. I've read (and am gradually re-reading) the nine existing novels in his Malazan Book of The Fallen series, and the tenth and final one is due at the end of this year. Esslemont is writing a companion series called Malazan Empire, for which there are currently two books.
I've also arrived a bit late at George RR Martin's A Song of Ice and Fire series, which I am loving (on book two at the moment). I'm quite a fan of Lee Child's Jack Reacher novels, and am just getting into Iain M Banks's Culture series as well. Used to love David Eddings' books, like The Belgariad and The Mallorean.