Grand Theft Auto IV/Assassinations

Once you complete Phil Bell's mission "Truck Hustle," you receive the "High-End Assassin" phone call. The Fixer directs the player to a pay phone across the intersection of Odhner Ave and Traeger Rd in Alderney (indicated by the Assassin's target icon), a block down from the weapons store. You can call the Fixer at any time (of course not while any other missions are active) and he will give you one of nine Randomly assigned jobs. Also of note is the fact that when a call is over, armor and a mission-specific weapon are spawned over the fence behind the pay phone. (It's not required to pick these up, but it is helpful.)

At the end of each mission, when your targets are (all) dead, you will get a call from the Fixer and your reward.

Migration Control
The Fixer wants you to take out a target a top of the Booth Tunnel in Alderney City (more specifically, the helipad). Grab the armor and RPG if you want and head toward the target. Once you reach the target open fire on the Helicopter trying to lift off. This is where picking up the RPG is extremely helpful. If you do use the RPG make sure as to aim it at the top rotor because you might hit the fence and waste a rocket (or kill yourself). Don't aim too high or you might miss it entirely. Once the helicopter is destroyed run up with a weapon and check the radar to make sure the red blip (your target) is dead. If not, well… you know what to do.
 * Reward: $3,000
 * Mission Specific Weapon: RPG

Bailing out for Good
The Fixer gives you the assignment of a high-risk target at the police station in Leftwood. After you get the job grab the armor or weapon if you want and head over to Leftwood. The target is being escorted into a car. You can take him out then or follow them a while, but it's recommended that you take him out before he gets into the car. Because there are police around, you are most likely to get one star once you start shooting at the target. Be careful to avoid killing the police officers in the possible ensuing gun fight or you will automatically get three stars and that's hard to escape from. You don't have to lose the police to get the call from the fixer giving you your reward money, but staying put could cause your wanted level to rise.
 * Reward: $3,000
 * Mission Specific Weapon: Combat Pistol

Derelict Target
Three men (your targets) have been lured to an abandoned building in Alderney City. Grab the armor and weapon if you want (this time it comes in very useful) and head over to the seven-story building. An alternate way to complete this mission is to heli-drop on the roof and work your way down. As soon as you enter the target area the targets and the other men there will open fire on you. The first target is on the ground floor but will flee to the basement of the structure. Take him and anyone else out and head up to the upper floors. Each floor has about two to three armed gunmen. It's not required to kill the non-targets, but it helps immensely to not have five people shooting at you. Use cover, first-aid kits, and the explosive propane tanks to eliminate them and the targets. By the time you kill the second target you might receive a star because of all the shooting. Your mission is complete once all three of the targets are dead.
 * Reward: $4,000
 * Mission specific weapon: Carbine Rifle

R.U.B. Down
This Assassination might be one of the harder ones. You are to kill a group of people in an alley between a police station and the Terroil plant in Actor Industrial Park. What makes this mission hard is that you have multiple targets and if you don't kill them all before they get to their bikes then you might be chasing more than one of them down. If you have some spare RPG's or if you’re good with the sniper rifle then use them to your advantage. Because it’s in close proximity to a police station, you’re likely to get a star or two.
 * Reward: $4,000
 * Mission specific weapon: SMG

Taken Out
Have you always wanted to ride in a limo? Well, you get to destroy one and its passengers in this action packed Assassination. Once you get the mission, pick up the armor and SMG although it is very hard to complete this mission with the SMG. You are to take out a limo in a caravan of cars randomly driving around Aldereny City. Once you get to that target you will notice that there are accompanying SUV's with the limo. You do not need to take out the SUV's. As soon as you fire a bullet or ram any car in the caravan they will all become aggressive and evasive and more importantly shoot at you. The best approach to this mission is to either block the car without hitting it or while its stopped at a stoplight then launching a RPG at the limo. A well placed rocket will take out the limo in one shoot.
 * Reward: $3,000
 * Mission specific weapon: SMG

Industrial Action
Have you always wanted to see an oil refinery? Well, you will be going to one, but you won't be taking a tour. Head over to the Globe Oil refinery in Actor Industrial Park and be prepared weapon wise beforehand by picking up the carbine rifle and armor. When you get to the street outside the refinery, the GPS routing will stop, but you still have to get to inside the fence and find the stairs up before any of the targets leave and you lose. As you approach the refinery in your car, turn right and go to the next left turn seen on the HUD. Turn left again in front of the building and go all the way to the end of the building then turn right and go to the other corner. Just around it are the stairs up. Stop before turning the corner and exit the car. A thug will be standing guard at the top of the stairs, but he will just stand there while you zoom in on him with your sniper rifle. Go to near the top of the stairs and you will get shot at by a bunch of thugs in the distance. Pick them off with the sniper rifle. Once you run out of targets, head to the center of the roof where some more stairs go up to the 2nd level. Take a catwalk there to find the last couple of targets. Don't forget to pick up the duffel bag with $10,000 from the deal before the mission's over (it’s on the 3rd level).
 * Reward: $7,500/17,500 (See below)
 * Mission specific weapon: Carbine/Sniper Rifle

Hook, Line, and Sinker
From the pay phone head over to the red blip along the shoreline in Westdyke. You should probably head over to the LCGC and get a combat sniper rifle before you get to the red blip. At the shore you will find a docked boat. Get in to boat. You will see a tropic boat in the distance. Your target is on that boat. You have two options from here. If you really good with a sniper rifle then by all means shoot from there or move up a little more to get a better shot. The other more action filled way is to alert the other boat by getting too close, then you have to gun the down in the ensuing boat chase.
 * Reward: $3,000
 * Mission specific weapon: SMG

Dead End
This time the fixer wants you to eliminate targets driving around in a Patriot (and possibly a second car). Do NOT take a cab to the location. Doing so will cause the chase to start as soon as you get out of the taxi and will result in your failing you the mission. You can take a taxi to a nearby location, jack a car, then finish the trip. Once you reach the target zone, chase the Patriot into an alley. The occupants will leave the patriot and go into a loading bay to take cover. Depending on which entrance of the alley you used, you will be boxed in by a second car. The occupants of this car will open fire on you if you don't gun them down soon enough. Once you can get out of the car safely, proceed to eliminate the original occupants of the Patriot.
 * Reward: $6,000
 * Mission specific weapon: Carbine Rifle

Water Hazard
This is maybe one of the more authentic assassinations your going to have. You are to take out a target on a boat in the channel between Tudor and Actor. While you are most likely not going to need the armor, it is of great help to get a sniper rifle because the SMG isn't the best weapon to use. Go to the target zone and get a good vantage point with your rifle (or if you like big explosions, an RPG will work). You only have to kill the target with the red arrow above him. Kill the target any way your heart desires, but make sure not to miss or it will send the boat speeding away and you fail the mission unless you’re already in a boat and are able to chase him down.
 * Reward: $3,000
 * Mission Specific Weapon: SMG