I would say Mortal Online 2 is the winner for me, but Dying Light (with I Am Legion mod) and S.T.A.L.K.E.R. Call of Pripyat (with Road to the North mod) are also very intense and will keep you at the edge of your seat and on your toes.
DayZ is a rather interesting game, I've watched a lot of videos like this one from Sergeant Merrell:
I would say Mortal Online 2 is the winner for me, but Dying Light (with I Am Legion mod) and S.T.A.L.K.E.R. Call of Pripyat (with Road to the North mod) are also very intense and will keep you at the edge of your seat and on your toes.
DayZ is a rather interesting game, I've watched a lot of videos like this one from Sergeant Merrell: