Yet another "Ranma 1/2 and World of Darkness" crossover question. Like the title and the poll ask, if Ranma was to somehow die and return as a Sin-Eater, which of the five Thresholds do you think he would most likely fall under?
To give a brief explanation of the whole concept, a Sin-Eater is created when a person with spiritual awareness (that is, the ability to sense spirits, ghosts and similar monsters) dies, but their head is intact. On the other side, this person is approached by a Geist, a spectral entity that is one half ancient human ghost to one half death spirit - that is, an animistic embodiment of death by a particular fashion (hence the five Thresholds - how you died determined which Threshold your spirit approached, and so which Geists can approach you in turn). This Geist offers the person a bargain; to allow the Geist to bond to their soul, which will bring them back to life. The drawback, besides the fact the Geist is now stuck with them until they die of old age (if they perish by violence or whatever, it can suck the life from another person and restore them), is that they can now fully see ghosts, ghosts are aware they can be seen, and so they come to the Sin-Eater asking for help moving on to the afterlife.
I can elaborate on the details of the five Thresholds if people want, but I think they're fairly obvious. In my own opinions, Ranma is most likely to end up a Sin-Eater of the Torn, Prey or Forgotten Thresholds, in roughly that order.
The Torn is because... well, Ranma 1/2 is full of violence. Ranma is repeatedly assaulted by various people, at least one of which actively proclaims he wants to kill Ranma. His fiancees all beat the hell out of him at the slightest provocation; Akane wouldn't mean to actually hurt Ranma, but, well, one good brick to the back of the head and Ranma would find himself in the Underworld before he or Akane realised what was going to happen.
The Prey is because Ranma spends a fair amount of time in the wilderness, and so exposes himself to danger through that method. Ranma's too tough and wilderness savvy to make it likely he could get bitten by a snake, mauled by a bear, or have ants burrow into his heart and chew it up from the inside out, but he could still get lost in a blizzard and freeze to death, drown, fall off a mountain and die or be crushed by an avalanche, or any of a variety of fatal mishaps while training on his own in the wild.
As for the Forgotten... to put it bluntly, Ranma has ridiculous luck. Look at all the sheer bizarro coincidences and accidents and mishaps that occur in the series, manga or anime, and can you tell me with a straight face that it would seriously be impossible for Ranma to run into the equivalent of buying a new car with its brakeline chewed through by a squirrel, digging up the only unexploded landmine in Britain, or being hit by a freak gust of wind and pushed to his death while having sex atop a fifty story building?