Again, not in any particular order.
1) Lord of the Rings, JRR Tolkien
A classic from the 1940s, arguably the novel that brought fantasy into the mainstream. Not the best written novel out there, but good enough to be re-read for decades. Christopher Lee and Ian McKellen agree.
2) Harry Potter-series, J.K. Rowling
A modern classic from the late-1990s. If you haven’t heard of the basics, what rock have you been under for the last 15 years?
3) Elric-series, Michael Moorcock
Classic sword-and-sorcery following the sickly, albino, warrior-mage Elric, last of the Melniboneans. Mostly a series of semi-connected stories, but all returning to Elric’s unwilling fight against both Law and Chaos, struggle to find peace, and struggle to find balance. The series spans decades starting in the 1960s, but was mostly written in the 1970s.
4) Lankhmar-series, Fritz Leiber
Classic sword-and-sorcery started in the 1930s and continuing into the 1980s. The current editions take the form of collected short stories and novellas set in Nehwon, charting the adventures of Fafhrd & the Grey Mouser.
5) Vlad Taltos-series, Steven Brust
Excellent series following Vladimir Taltos, sometime assassin, witch, swordsman, nobleman, and minor crime lord along with his familiar, a flying reptile called Loiosh, as they navigate the Dragaeran Empire, in which humans are second class citizens at best.
6) MYTH-series, Robert Asprin
A comedic fantasy classic started decades ago and continuing after Asprin’s death (Jodi Lyn Nye is putting out more in the series based on his notes). Slapstick mixes with puns and parody references as the characters stumble through the multiverse.
7) Discworld-series, Terry Pratchett
Quite possibly the best comedic fantasy series ever. Pratchett mixes serious social commentary with his own particular brand of British humor into a world and series that has captured the hearts and minds of fans around the world. He follows several groups and major characters, so summarizing the series is effectively impossible.
8) Neverwhere, Neil Gaiman
The novel that moved Gaiman from the graphic novel world into the mainstream. It follows Richard Mayhew as he slips between the cracks to discover a whole other world beneath the one we are used to seeing (London Below). The whole book is based on the London Underground map and was written concurrently by Gaiman with a BBC mini-series.
9) American Gods, Neil Gaiman
Considered by many to be Gaiman’s masterpiece. The novel posits an America in which the Old World gods are living, weakening, but living. The rest covers some gods’ attempts to recover their old power.
10) Videssos-series, Harry Turtledove
What happens when a pre-imperial Roman legion is transported to a different world in which magic works? What if the nation they land in looks a lot like the Byzantine Empire, complete with Norse, Mongol, Carolingian, and other recognizably post-Roman neighbors? That pretty much sums up Videssos.
11) A Night in Lonesome October, Roger Zelazny
A piece of comedic urban fantasy by one of the masters. Told from the perspective of a dog familiar, the novel follows his wandering around town, chatting with other animal familiars about their masters (many of whom are recognizable historical or legendary figures), and finding supplies needed by their masters. Meanwhile, the masters are trying to open or close a portal to other worlds on a night in lonesome October.
12) A Song of Ice and Fire-series, George RR Martin
The series that inspired Game of Thrones. Not for the faint of heart, each book is massive, everyone dies, politics abound, and it is much more complex than the show. But, definitely worth it.