I have come to have an appreciation for naval/maritime tales.
Whether it was growing up reading about Horatio Hornblower, or coming to appreciate the Capt. Aubrey stories of O'Brian as an adult, there's just something very cool about stories set upon the sea. 
Yet, it seems to me that is an underused setting for high fantasy in contrast to all of the earthbound quests on foot or horseback...
the ones which immediately come to mind:
LeGuin's Earthsea (series)
Hobb's Liveship Traders (trilogy)
Lynch's Red Seas under Red Skies (sequel to Lies of Locke Lamora)
Naomi Novik's Termeraire (part of the series is set on British naval ships)
Donaldson's The One Tree
some of Anne McCaffrey's Pern books have a sea or seaside setting...
Which ones am I missing?