novels with knowledge of the future.

#1
can someone reccomend me any? it doesn't matter if it is because second chance/timetravel or being transported to a game world.

i am looking for serious, (but not gritty mind you) series like dungeon defense and amber sword. if you do not know about these two stories, basically i am looking for a more do or die type of story, with of course occcasional breaks. the main character has to be an active player in the story. i know about dungeon hunter, king of the battlefield and reincarnator.

please give me a short summary and why you like the story as well if you don't mind. thanks for the help.