If you wanted to reread the Cosmere, I would suggest rereading it in the order you first read it in.
Or just reread your favorite ones over and over. (I'm I my seventh round of tWoK, I've gotten through WoR six, and OB three. I'm always listening to one of them on Audible, and pick up something new every time).
I also have to mention tWoT. That is sure to keep someone busy for a while. And they are really good, if you have the patience to read them. And Sanderson's non-Cosmere stuff, though not as complex, are still amazing.
But stuff besides Sanderson and Jordan is hard. I'm most experienced in the realm of YA and children's. I finished reading Fahrenheit 451, and it was one of the best books I have ever read. It's dystopian, and was written in the early 1950s, but was mind blowing. And I've heard the Rira Chronicles by Michael J. Sullivan are amazing.
Oh, and there's this guy called Brandon Sanderson, and if you haven't read his books, go read them, because they are absolutely amazing.