1) The Hobbit (Tolkien - not as epic a tale as the Lord of the Rings, but pretty epic all the same - and better written in many ways (far less long, dull conversations and songs). It also includes themes of the danger of lust for money and power corrupting and leading even good people to do bad things - also leading some of them to their deaths.
2) The Lord of the Rings (Tolkien) - Tolkien created the first fantasy world so detailed and comprehensive that it was believable, down to a history from the earliest times, a mythology and languages. The Lord of the Rings is certainly the greatest fantasy epic ever written, despite it's minor faults (could have done with some editing at some points to make it shorter and flow better)
3) Chronicles of an Age of Darkness series by Hugh Cook (especially 'The Witchlord and the Weaponmaster' and 'The Wizards and the Warriors' - these are fantasy with medieval technology and society along with genuine magic but in a post-apocolyptic world in which old technologies and robots are seen as 'magical wonders' and 'demons' or 'gods'. The original small paperback editions looked like generic rubbish and sounded like it from the blurbs on the covers, but in fact Hugh Cook was one of the greatest fantasy and sci-fi writers ever - able to write books in which you would laugh at one point, cry at another and be horrified or terrified at another without any incongruity. Much of his books make fun of real society and history and common hypocrisies and cruelties and ideologies (including everything from religion to neo-classical/neo-liberal economics). Another theme in the books is the chaotic nature of reality in which plans made by individuals never work out - because everyone else has their own , different plan - and random chance and events that turn established 'certainties' upside down intervene all the time)
4) The Silmarillion (Tolkien - see The Lord of the Rings above - though The Silmarillion, written in the style of a medieval chronicle, is tough going at some points, it's worth it for the epic battles that include demons, gods, dragons, werewolves, vampires, orcs, trolls, humans, elves and dwarves, wizards, heroes and magical weapons - and for the sagas of heroes)
5) Unfinished Tales (Tolkien - Middle Earth sagas of some of the great heroes of the first and second ages, like Turin Turumbar
6) Elric and Eternal Champion books by Michael Moorcock - Like Tolkien, Moorcock drew inspiration from viking sagas (especially Sigurd from the Volsungs saga). Both Turin and Elric have a black sword. Both end up killing friends and loved ones with the sword, leading them to despair.
Moorcock also seems to have been influenced by Poul Anderson's 'Three Hearts and Three Lions' (see below) , though Moorcock's idea of chaos versus order is far more developed, including Gods of Chaos and of Law and the idea that neither one nor the other is good, with the best aim being a balance between the two that leads to neither the unchanging stagnation and lack of freedom of complete order, nor the
Moorcock also builds on Anderson's idea of the "multiverse". In Anderson's books only two planes of the multiverse are developed (though he says there are many). In Moorcock's books many are - one for each 'eternal champion'.
Though each of Moorcock's eternal champions (the aspect of the eternal champion found in each universe of the multiverse) share things in common, they all differ too.
p.s don't bother with Moorock's 'Jerry Cornelius' books. They're unreadable random, rambling pretentious ****. Needless to say literary critics, who had mindlessly condemned all fantasy literature as 'not serious writing' loved the Cornelius pap.
7) A Game of Thrones (George R.R. Martin). Martin may have given himself the R.R bit just as a sales gimmick to sound like JRR Tolkein, but his books are also very well written, with a world just as detailed and believable as middle earth, but a very different, gritty style. Each chapter is written from the point of view of a different character, the machiavellian machinations of different characters and factions are entirely believable, the characters are all believable and change over time due to their experiences and interactions with others (just like real people) and Martin's books are never predictable. Any character may live or die at any moment and you will get some shocks reading his books.
Unfortunately his last couple of books in the series have become far too long and overly detailed and should have been edited down a lot. If they had been he might have finished the (how many book?) series by now. They're still more than well worth reading despite these faults.
8 ) The First Law trilogy by Joe Abercrombie (Before they are Hanged,etc ). All Abercrombie's books are fantastic, not just this series. The first book seems lat first like generic fantasy cliches - but this is what Abercrombie wants you to think and the truth is very different - and you only find it out a little at a time, without the full truth coming out until the very end of the last book. Very funny at some points, very gruesome or sickening at others. Like Martin, Abercrombie writes each chapter from the point of view of a different character and there is some machiavellian politics going on, but his books are very different, even if just as gritty as Martin's in many ways.
9) Three Hearts and Three Lions by Poul Anderson - This is the first fantasy book (as far as i know) to refer to chaos fighting order - and to the multiverse. It's fairly short but well written. A partisan in an occupied European country during the Second World War is knocked unconscious during a fight with German forces and wakes to find himself in a parallell world where the forces of order and chaos are fighting one another , with elves, humans, dwarves and trolls involved, among others. He finds that this parallells the war in his own world and the outcome in one may affect that in the other. A troll living in a cave which can regenerate and which can only be injured by fire also features.
10) The Broken Sword by Poul Anderson - This book seems to be based on the viking saga of the Volsungs, much like Aragorn in Tolkein's LOTR , Turin Turumbar in Unfinished Tales and Elric in Moorcock's epic. It's extremely well written and worth reading in it's own right though. A human child is switched for a changeling by an elf lord, who then raises the human child as his own, for reasons that will only become apparent later in a war between the elves and the trolls.
11) The War of the Gods by Poul Anderson - Again loosely based on Norse myth, this is a fantastic book about a human raised as a foster child of giants who becomes involved in a war between gods and giants.
12) Warhammer fantasy books (black library series) - I expected these to be mere half-hearted advertising for Games Workshop / Citadel miniatures and the Warhammer and Warhammer Fantasy Role Playing Games. I was wrong - many of these books are well worth reading and the Warhammer world actually builds on and refines many of the ideas found in Michael Moorcock's books. The idea of the four Chaos powers which each have their own aims and beliefs and practices and are enemies of one another is particularly good - with two lots of two paired opposite enemies. If they unite as 'chaos undivided' then the world really needs to worry.
Some of the authors are much better (or worse) than others.
Dan Abnett's books are fantastic and much more subtle than some other writers'.
Brian Craig's Zaragoz series and others are the subtlest and best written of all. The threat of chaos coming from the most powerful and the way those fighting it often have to fight desperately hard just to win small victories seems to parallell the real world.
Personally i'd give all the Gotrek and Felix stories a miss, except for the ones in the 'Wolf Riders' book of short stories, which are quite good. Other than that it's tediously predictable that Gotrek will massacre everything with ease and so quite dull.
C.J Werner's books about vampires and necromancers are mostly more sickening than riveting, the constant gore is a poor substitute for the subtler spine-chilling fear and menace in really good horror writing (which only ever shows early on in some of his books) ; and the plot frequently makes absolutely no sense (e.g at one point in a war between vampire counts and the Empire the chief Vampire count docks in Imperial ports constantly in his notorious 'black ship' without any Imperials even trying to give him a good burning, staking or holy water shower).
Most of the other writers are somewhere in between, though there's one writer who mostly writes about expeditions to Lustria against the lizardmen whose books and short stories are terrible rubbish (i forget his name).