My theories on the end of Breaking Bad, not in order of plausibility.
- Jesse or someone he cares about kills him face to face.
- One of those people kills Walt and then takes his place as the new Heisenberg (ie. Jesse, Skyler or Walt Jr.)
- He dies of cancer alone in a dingy hotel room and we see his last breath with a look of resignation that he brought himself to the place he is right now.
Those are the ones I think are most plausible.
ps. as of this moment I have not seen the new episode yet, so don’t spoil me.