The Hidden Blade Assassin's Creed in Depth

http://www.youtube.com/watch?v=pYq4IWr_CRA
[Front-paged by stabguy]

Early Death
After the Banker appears in the memory he walks to the party. He can be scared into running away. Chase after him for a good distance. When you get within a few meters he stops. The target is supposed to teleport in place for the scene, but since you are so far away from the scene location he doesn't (probably because the party area isn't modeled in the game from being so far away). Now the only way to kill him is moving him into water. He falls nearly two hundred meters. Here's the thing: If you get about sixty meters away from him horizontally you desynchronize with "target lost". There are probably a few reasons why that's so, but in any case you don't desynch directly from killing him, making it a successful Early Death.

A Hole in One
This took a long time to perform right. Start off by stealthily killing the guards in the area. Then throw their bodies to the ground below to lead to the well nearby.
Now place the target at ground level, as was shown in a previous video, where he can be lured by the dead bodies.
http://www.youtube.com/watch?v=Dq9j-ixTH2w
Having the target follow the bodies is tricky. He doesn't seem to notice some of them that much, might have to do with distance and object modeling (or he just takes too long to inspect the bodies). Now for the assassination. A fatally high jump from the top of the nearby pillar will have you safely land in the well to ledge assassinate the Banker. This is A Hole in One, loosely related to Eagle Strike.
It was pioneered by IanXO4.
http://www.youtube.com/watch?v=oE-92iM7KiI
And used as an assassination style by Stabguy.
http://www.youtube.com/watch?v=O3cP6atjiOA

Longshot
I had intended to lure the Banker using dead bodies, but instead chose the easier way of moving him. At the start of the assassination quickly stealth kill all guards that could expose you during the setup. For a short while the Banker is unresponsive and can't detect you. You can grab him without being exposed. Move him to the place shown and release him. You'll need to use a smoke bomb or two to keep him in place long enough to lock onto him. Quickly kill off the archers that can see you and lock onto the target. The distance you desynch at is sixty meters. There is a brief moment before you desynch, so you might succeed at sixty meters, but in this setup from where Ezio is standing the farthest distance the target got was fifty nine meters.

Stunt
At the beginning of the assassination quickly climb up the roof of the building and kill the archer. Then run off the corner and assassinate the target. If I remember right I got this the first time I tried it. But in this video it happened a little different. In the original try I landed right behind him. But in here I landed to the side of him (good thing I locked on). In both cases I got the stationary high profile animation.

A Splitting Headache - Pre-assassination
This clip is related to the "Migraine Collection", where Cesare Borgia is killed by a thrown heavy weapon before the developers had intended his scripted death. In the case of Ercole Massimo, the developers had intended for you to fight past a group of Hermeticists in a pit, and then assassinate a cowering Ercole in an uninspiring, scripted kill. That's too boring for The Hidden Blade...

http://youtu.be/iRLFhK6NQGM
[Front-paged by stabguy]

The Serial Offender mission is a memory where you assassinate a doctor. This memory is part of the storyline in sequence four. After the scene that starts the mission the doctor appears in place in front of a doctor shop. He just stands there and won't move unless you either do the mission the way it was intended by following where the courtesans are pointing or locking on to him. I'm not the first person to have discovered this, but I did discover it independently.

The Fast Route: This is the quickest way to assassinate the target. It can probably be done a little faster, but I was just showing an example.

Tripwire: For this you want the target to run a certain route. I lock on to him from the opposite direction to make him run there. When he starts running climb up the building but don't run ahead of him or he will turn back. I aim from a small platform (since the gun is level to the target's head the timing has to be just right).

49 Meters: The mission desynchronizes at fifty meters, so I get a long shot with the hidden gun. I climb to the top of a high building to get a clear view of the target (because if there is anything blocking the targets view the shot misses).

Stunts: I perform two stunts, one near where I perform the tripwire assassination, and the other from the same building where I did the 49 meter shot (during that I accidentally jump in a haystack).

Poetic Justice in the Form of a Mysterious Death: A mysterious death is very easy for this mission, but I did it mostly for the sake of poetic justice. I tried to increase the challenge by being notorious. I also took the same path that I took for the fast route instead of taking a route that would have avoided any enemies. It's poetic justice because of how I used a doctor's tool against the doctor. I purposely used up all my poisons so that I would have to buy the poison from the doctor standing behind the target (yes yes, it looks like I bought the poison from the target himself).