I expect a thread about Science Fiction to get zero responses but I'll throw this out anyway . . . . the Mars Trilogy by Kim Stanley Robinson.
Red Mars, Green Mars and Blue Mars- written over a decade - with a time frame spanning 200 years - is more than 2000 pages of reading altogether.
All three novels won the highest awards for the best of science fiction in the years they came out and the Trilogy is considered a milestone in SF literature.
It combines a soap opera longetivity (some would use the term space opera instead) of its primary characters with a pretty technical conversation about societies, political movements, environmental movements clashing with industry, the role of science and how all of that meshes with the colonization and terra-forming of Mars.
If you consider yourself an environmentalist or left of centre in most debates, you'd probably be attracted to it even more.
Kind of a high brow read, one reviewer describing it as "dream-like" and using that term in a not so positive manner. So . . . . its not for everyone but a fascinating plot, rich characters and, as I said, an elevated conversation level on a vast array of topics.
Just take your time with it, get into that "dream-like" state, and you'll have fun with it.
A review of Red Mars at Amazon.com
If you like your SF less technical, then you can do no worse that Isaac Asimov's famous "Foundation" series which he wrote over a period of many decades.