I will add my vote to the Mistborn Trilogy. For anyone either new to fantasy or new to Sanderson, The Final Empire (Mistborn #1) is where I always point.
Great characters, completely unique world like nothing you've ever experienced, completely unique magic system unlike anything you've experienced, and a fantastic plot.
I'm not as big of a fan of the 2nd and 3rd book of the trilogy, but I love Mistborn Era 2.
Whether you go on with the series or even Sanderson, the first book can stand on its own as one of the biggest "must-reads" in fantasy.
ETA: For audiobooks, I will always recommend the Dresden Files if you are looking for shorter, fast-paced books. A world that starts small and slowly grows over the course of the 17 books to one of the biggest fantasy worlds out there. But the true genius of this series is the character work. No other book has characters I love more than the Dresden Files. I could give you a proof as to my love of the characters, but that would be a massive spoiler.