I made an assassin character, and I came up with an interesting idea. What if her contractors were you, the forum users?
A simple forum to fill out:
NPC Name:
Home City/General Area:
(Optional) Reason why you want them dead?:
Payment:
Anything Else:


I ask that you only ask for Non mod characters, or ones that don't require progressing in quest lines. Essential or not.

List of the already dead:
Hastrel Ottus
Lazare Milvan
Count of Skingrad-That was a nice and challenging sneak into the castle.
Glarthir
Tamika(She turned up dead randomly)

Target: Lazare Milvan
Location: Skingrad
Reason: He's a stuck up, asinine S'wit of a 'noble' who thinks everyone on the face of Nirn is beneath him.
Payment: 5,000 gold
Anything Else: Remove his clothing and give it to a beggar. Make sure his body is found in an extremely embarrassing way (the more embarrassing, the better). Do this, and you will receive a bonus of 5,000 gold. Do not fail! If you fail to kill him, do not survive. If you survive, you will come to wish you hadn't. Go now, Parthenia. Go, and may Sithis be with you.

Good news, Essential NPCs are no longer safe from Parthenia's blade. And She will get right on that contract.
EDIT:
Lazare lies dead. His clothing has been removed, and he is laying in an embarrassing position. The clothes on his back were given to the beggars around Skingrad. Parthenia is glad to have taken the life of such an arrogant noble. She woke up in her tent to find the payment.

No screenshot of the newly deceased?

Sadly I cannot post one without getting in a lot of trouble due to by body replacer, but when I get a contract that leaves their clothes on, I can.

Lol that's a bummer

Name: Lucien Lachance
Home City/General Area: Unknown
Payment: 8000 gold
Anything Else: (may not be possible if you have slept since your last contract)

I could, if there was a way to find him without going through a good part of the Dark Brotherhood after the first encounter.