To cite VERY few of my favorites -
"City of Thieves" by David Benioff - This book is sort of a melange of historical fiction (or is it?) and adventure...it is incredibly well written and would make an incredible movie if the right person were to pick it up. I usually don’t read historical fiction as I am also a sci-fi/fantasy buff, but this one more than worked for me.
In the Sci-fi category, the very top of my list has to be the "Hyperion Cantos" by Dan Simmons - Far too huge of a story for me to sum up in a few sentences, but I think anyone who has read it would agree that the series is a modern sci-fi classic. Dan Simmons is one of those writers...not unlike Frank Herbert, who had incredible amounts of details, information, sub-plots, etc....but, unlike Frank Herbert does it in a way that does not drag on or interrupt the plot....somehow at the very end of it all, everything is not only connected but concludes into my absolute favorite ending. Highly recommended!
I have to also include the “Imagica" books by Clive Barker
While he is pretty well known for his horror stories and movies...this two book series would fall under the fantasy section, although in true Clive Barker style there are some horrific and sexually perverse parts. Barker actually names it as his favourite of all his writings. Imagica chronicles the events surrounding the reconciliation of Earth, called the Fifth Dominion, with the other four Dominions, parallel worlds unknown to all but a select few of Earth's inhabitants.
If you haven’t read it, you should put it on your list.
And I will leave you with one more from my HUGE list of favorite books...in the Sci-Fi category it would have to be “Snow Crash” by Neal Stephenson.
This is another that would most definitely be in the modern sci-fi classic category...I know a lot of people probably have read this one if they are into sci-fi, but I just had to add it as it is one I like to re-read every few years or so...it never seems to get old. The main character, Hiro Protagonist, discovers the name of a new pseudo-narcotic, "Snow Crash", being offered at an exclusive Metaverse (virtual reality world) nightclub. Hiro's friend and fellow hacker falls victim to Snow Crash's effects, which are apparently unique in that they are experienced in the Metaverse and also in the physical world. Hiro uses his computer hacking, sharp cognitive skills, and sword-fighting to uncover the mystery of "Snow Crash”.
That’s all for now...I’ll post more if you like.