I don't know how I missed this thread, but I likes it.
I strongly second Fenrix's recommendation of Tiptree. I'm most familiar with her short stories and novellas, but definitely check out that link to the Lightspeed story as it's a good introduction to her major themes (particularly the question of biological determinism, and the relationship between love, sex, and death)
Sticking with just novels and not short fiction, I'll also add:
- Margaret Atwood's
Oryx and Crake, which is really well-researched posthuman, postapocalypse SF with an eye toward genetic modification. Also,
The Handmaid's Tale is a classic.
- Ursula LeGuin's
The Left Hand of Darkness (and everything else in the Hainish Cycle, really).
- Octavia Butler - Xenogenesis trilogy (or really, everything she wrote)
- Check out Pat Murphy -
The Falling Woman isn't a bad place to start
- Pat Cadigan writes great cyberpunk. I'm more familiar with her short stories, but I hear her novels are great too.
- Nnedi Okorafor's
Who Fears Death - sci-fantasy, but it won pretty much all the awards and is on my to-read list.
- Also, you can't go wrong with Mary Shelley's
Frankenstein if you want to follow SF back to its roots.
I think it's aged very well, too. I still reread it every once in a while.
ETA: and yeah, pick up Lightspeed's
Women Destroy Science Fiction anthology/mega-issue. Aside from all the great stories, the nonfiction section contains reams of recommendations for outstanding women-authored SF to fill out your list.