Modern person time travels to Ancient Rome/Greece/Egypt etc

Hiya! Looking for a book where someone from modern times goes back in time to Ancient Rome, or Pompeii, Greece, Egypt or similar ancient cultures. What are the best books you’ve read that fit this premise? Preferably with flawed protagonists who don’t get everything right just because they know the history. Open regarding the protagonists’s gender, sexuality and other factors. I’m not picky.