I recently read two books by Brandon Sanderson and really enjoyed them: The Way of Kings (the first and so far only book released in a new series) and Mistborn: The Final Empire, the first book in a completed trilogy. I'm on the second book in the trilogy, it's a fantastic follow up.
My favourite fantasy series is George R.R. Martins "A Song of Ice and Fire".
Are you looking to get these for someone as a Christmas present? Ebooks or paper books?