The Top 25 Fantasy Books list selects from a wide range of fantasy, from epic fantasy to detective fantasy, from well known series to obscure Fantasy, and from old fantasy books to brand new fantasy releases.
#1: A Game of Thrones (George R.R. Martin)
#2: The Malazan Book of the Fallen (Steven Erikson)
#3: The Name of the Wind (Patrick Rothfuss)
#4: Tigana (Guy Gaveriel Kay)
#5: Lord of the Rings (J.R.R Tolkien)
#6: The First Law (Joe Abercrombie)
#7: The Wheel of Time (Robert Jordan)
#8: The Farseer (Robin Hobb)
#9: The Darkness That Comes Before (R. Scott Bakker)
#10: Mythago Wood (Robert Holdstock)
#11: Jonathon Strange & Mr. Norrell (Susanna Clarke)
#12: His Dark Materials (Philip Pullman)
#13: Lies of Locke Lamora (Scott Lynch)
#14: Chronicles of Thomas Covenant (Stephen R. Donaldson)
#15: American Gods (Neil Gaiman)
#16: Earthsea Cycle (Ursula Le Guin)
#17: Abhorsen Trilogy (Garth Nix)
#18: A Sword of Shadows (J.V. Jones)
#19: Memory, Sorrow, Thorn (Tad Williams)
#20: Acacia (David Anthony Durham)
#21: Magician: Apprentice and Magician (Raymond E. Feist)
#22: Heroes Die (Matthew Woodring Stover )
#23: The Dark Tower (Stephen King)
#24: Dresden Files (Jim Butcher)
#25: Amber Chronicles (Roger Zelazny)
Source: http://www.bestfantasybooks.com/top25-fantasy-books.php