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.
Someone else already mentioned 11/22/63, so I’m going to go with The Guns of the South by Harry Turtledove. You can go back in time or forward, but no more and no less than 150 years either way, which is why the South African white supremacists who give the Confederate army AK-47s don’t turn up until 1864 (they stole the time machine in 2013, and were ready to execute their plan by early 2014).