Add to the top of the list re: ZERO - STARTING LIFE IN ANOTHER WORLD.
Like anything popular, the player-trapped-in-game genre has been diluted as it's expanded, becoming glutted with a host of people trying to cash in on the trend. And, honestly, when I first saw this book, I figured it would be another one of those, but the interior art was gorgeous so I gave it a shot, not really knowing anything about it.
I'm glad I did, because while it is another player-in-game fantasy, it's very tongue in cheek about it. Neither the series nor the main character takes it too seriously because, as a citizen of modern-day Japan, he's fully aware of the genre and that touch of humor is welcome. In addition to that, the series has something of an original twist of the genre--one that gives the series its name--the main character, Subaru, is disappointed to find he doesn't have any special powers or skills (as most otherworldly heroes) do - until he's in a situation where they'd most come in handy... and he's killed. No special fighting skills after all. Instead, he wakes up as if nothing has happened - and indeed, nothing has, for it turns out the entire world is reset to the point where he first entered it when he dies, leaving him with the knowledge he's gained in his previous run-through so he can continue on and try again.
The first volume of the manga doesn't get very far into the world--my understanding is that only two volumes were published before the series changed publishers and that this first series only adapts part of the original novel--but I'm looking forward to the next one and I sincerely hope Yen Press continues to adapt the Square-Enix-published manga after finishing with the one Idea Factory-published.