This list will no doubt be woefully far from comprehensive. I cannot possibly remember every book I've ever thought I'd like to read someday. And occasionally instead of listing specific titles, I'll just list an author who's written a few things I want to read. And um... I have some books given to me by friends, some of which I'll list and some I won't. But I'll probably get around to reading them someday even if I don't mention them here. Note: there may be some books on my Amazon Wish List that I don't list here.
You know, I used to get catalogs from the Science Fiction Book Club, during the 90s, and I'd go through them and circle anything that sounded interesting, hoping I'd have enough money to buy all those books someday. And now I don't think I have any of those catalogs anymore. Which is a real shame, because they would have come in handy for reminding me of things to add to this page. Sigh. But there are various other ways I've learned about books I might like to read, such as Entertainment Weekly, or Sword & Laser, or random online lists* of important books, etc. And of course, some books I've just always known about.
*Generally I go through online lists I come across (usually links shared on facebook), and just add maybe a few titles or authors to my "want to read" pages, if they sound like they'd be of particular interest to me. Unfortunately, I didn't think to include links to such lists until this one: 100 Must-Read Sci-Fi Fantasy Novels by Female Authors. Maybe I'll be able to rediscover lists I've consulted in the past, and add links here, maybe not. But at least anytime I read such lists in the future, I should remember to put links here.
Okay, here are some more lists I've collected, though I haven't necessarily read through all of them, or added titles from them to my lists of things to read.
8 Books about Alien Invasions that Take Place Outside the U.S.
21 of the Best Horror Books by Women
26 Underrated Sci-Fi and Fantasy Gems You Shouldn’t Miss
50 of the Greatest Science Fiction & Fantasy Debut Novels Ever Written
100 Great Works OF Dystopian Fiction
The Best Fantasy Novels of All Time
The Best Sci-Fi Books of All Time