^ [.. magically and unexpectedly appearing from above.
Barring the fact a weight might not materialize out of nowhere to drop on your assailant’s head, but you had to it, you would choose to be up on the roof, rafters, or tall ladder and drop something on their head to cave their skull in? Because you figure it to be effective in killing them, maiming them to the point they can’t do any more damage, of because you do not have to see them or interact with them physically to vanquish them?
As I mentioned, my selection criteria are mainly about being effective, not risky, quick and painless, generally in that order, and given your stipulations that I really have to kill them.
Of the options you mentioned, the weight seemed to best fit my criteria, especially in the form I selected. But of course I also chose it ironically, because the main point of the joke was how it was utterly effective yet also utterly improbable and unexpected.
My reason is wanting to be as effective as possible, which wouldn’t apply if for example there were a good chance to miss. I don’t want to avoid seeing and I only want reduced interaction because to me it strongly implies risk of failure and/or getting hurt or killed myself (or others nearby).
If you just want to know which experience I would prefer, given certainty of success, no risk to self or others, and no moral ambiguity that killing them is necessary, then hmm….
I think it depends very much also on whether I have some degree of anger or malice towards them (in which case I might not mind them suffering so much), as opposed to considering them possibly misguided to do violence, in which case I’d like it to be quick and painless for them.
So with malice, a huge weight also sounds really satisfying. So does casting them from a great height. A bludgeon could be good if it were something like a large medieval mace. If you’re willing to extend the knife to a large medieval sword, that would also suit me.
Without malice, we’re back to the huge weight if it’s big enough to kill them, or the very high fall, since I imagine those being the least painful.