I've only read Ringworld from that list (earlier this year). The story did a cool job of introducing the concept of an orbital ring and giving it a sense of scale, plus introducing some other cool concepts/ideas. It also introduced more species and planets and technology that made sense for a big Star Wars-like space opera book series. It was definitely dated as far as how female characters were written, though.
I thought Consider Phlebas did a better job of using a Ring World without it being the whole plot on its own, but I suppose Ringworld had to walk so others could run with it.
The Annihilation / Southern Reach sequels were short enough books that I figured I might as well read them despite some people not liking them. They're definitely different from the space related stuff I normally pick up, but I'm glad I read them.
I thought they were good! They both made me not want to put them down and kept weaving the horror and mystery together, closed out some of the loose ends and answered questions, but also opened a lot of new cans of worms.