NPR has a vote on. Go and see which ones you’ve read, which ones you love, and which ones you go “Wow, they put that on there?!”
Apparently sci fi folks are strong advocates for their favorite authors.
Note: My favorite authors ARE on the list, under The Liaden. And my two runners-up are, too. My husband’s favorite fantasy book of all time is also on the list.
My favorite books by my favorite authors (though you probably need to have read the others to understand these, since they come towards the end of the story line) have been put together in an omnibus.