Do you want to come in my basement :)..
breathes and smells your neck :)...
Come closer... :)... I want to touch you :) .... I want to see you bleeding, jk :)...
I want to kill you...by laughing :)....
starts firing up chainsaw
I am a friendly and nice person :)... You should come to my basement :)...
:)...
by Turncoat"such a female thing"
A shame too, poison is such a fun topic. Symptoms are far more fun to watch or read about than just bleeding, and it has far more creative uses than a typical weapon.
Arguably more dramatic for storytelling as well.
I don't know much about poisons, but I'm interested to learn. Care to share your knowledge on the topic?
Are there any truly undetectable poisons that won't show up on a tox screen. How easy or hard are they to obtain and what are their affects?
Which poison do you think would be the most interesting to kill someone with and why?
Posted two examples in your perfect weapon topic. 
Poison itself I enjoy because of the sheer variety of ways that they work, methods of application, etc. Poisoning food and drink is more commonly thought of, but you could apply a poison to the inside of someone's wineglass, could tip it onto something sharp, it can be inhaled in powder form... The beauty of poison is the variety. A knife stabs and slashes while poison can outright make your own body turn against you, if not turn your mind against you instead.
Majority of poisons these days can be detected, but if you're smart about it they'll never suspect it was you. Poison doesn't exactly leave fingerprints like a murder weapon or a bare hands killing (assuming the murderer in question hasnt burnt them off by then). Just don't leave an obvious paper trail as to how you acquired it and pick victims you have no connection to, preferably in ways where the victim never sees your face.
Save for more typical chemical poisonings, getting it's the hard part. If you can make a nice secret little hidden greenhouse setting you could cultivate your own. Ergot is a mold that grows on wheat in specific damp conditions (I may be mistaken here), was what led to the development of LSD, and can be prepared into whatever food you make with said wheat. Many poisons are either something medically useful used "improperly", if not something someone might casually own themselves. Drugging someone is effectively poisoning them as well, and I personally find it interesting to watch a person behave unnaturally.
History and novels are filled with tales of poison. The infiltration aspect of it adds an extra dimension of drama for the stories.
