Sword Art Online - 8
I'm not going to lie, it is kind of interesting to me on how the players have integrated into the system and have adapted to the world before them and have a plan of some sort. The lesser-experienced players have done things like open-up shops and businesses inside the game while they let the more experienced players handle the problem of finishing the game and setting everybody free. They've taken the world before them and sort of reshaped it a bit to allow themselves to fit in until they can get out.
The show does that part all right, I guess. But again, I could probably have taken this a lot more seriously if the main protagonist was a noob who had never played a game like this before (LIKE KLEIN!!!!). Make the focus on someone struggling to adapt to that kind of life. It's hard to get a real grip on the whole "survival" aspect of this show when our main character is getting it all good with the ladies and is seen tanking hits from other players and is dubbed a beater (bahahaha). It just doesn't work.
So now there's less than 500 players left. You can just barely call this an MMO any more.