i am yet to see a mutiplayer shooter have maps and gameplay like duke nukem 3d (its been what... 16 years now?)
so many hiding places and tunnels looping into each other, so many platforms to climb for great weapons, so many moving ledges, elevators, platforms, windows that activate on buttons. personal non mobile weapons like activated bombs and trip beams that can be placed in strategic places, even on the movable objects.
multiplayer competitive shooters went downhill :(