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.
Time War should come with a disclaimer IMO… the prose is lovely but if you need plot and character development, it isn’t the book for you.
As someone who usually is into plot and detailed magic systems, I still loved it.