American Gods by Neil Gaiman

Norse Code by Greg van Eekout

The Gospel of Loki by Joanne M. Harris

Wild Card (Etudes in C# Book 1) by Jamie Wyman

Hunter Sacrificed (Wild Hunt) by Nancy Corrigan*

*Nancy has a second Norse-themed series called Elemental Desire also.

I Bring the Fire: Parts I, II, III, & In the Balance: (A Loki Series) by C. Gockel

The Unleashing (Call Of Crows Book 1)  by Shelly Laurenston*

*Shelly has a second Norse-themed series called The Gathering also.

Very Much Alive: True Destiny, Book 1

The Elsker Saga by S.T. Bende*

*S.T. Bende  has a second Norse-themed series called The Ære Saga also.