My pick would have to be the A Whole Nother Story trilogy, in which (spoiler warning) you can only travel back in time. But because time is in a loop of sorts, if you go before the beginning of time, you will be at the end of time. From there you can go back to any time you want to. And time paradoxes cannot be produced. Plus, your memories from the previous timeline exist as well as the memories from the new one.
The Book of the New Sun.
It’s not really about time travel, and doesn’t make it a huge part of the overall plot. It’s something that’s sort of present, and relates to events that happen (or happened?).
I think most books with time travel focus on that specifically, so it’s interesting reading a book that has it while not really making it explicit or even focusing on it much.