The currently most-recent game in the Hitman series, Blood Money is only slightly dated (from 2006). However, in addition to buying the game itself, it's also possible to play this game through the Gametap online service.
Hitman: Blood Money places you in the shoes of Agent 47, a bald, bar-coded clone assassin used for the most dangerous and discreet assignments. 47 works for the Agency, a contract-supplying organization that hires him for hits on certain important people. To that end, 47 must take out his targets as quietly and discreetly as possible.
Each mission is in itself a sandbox of sorts. There is a large area with a certain number of guards and civilians, as well as your targets. In each mission, you must scope out the area and examine patterns that people move in, who is allowed to go where, and certain areas that offer tactical advantages. Some areas require certain uniforms to get in; to this end, 47 can take costumes off of people that he has knocked out or killed. For example, in one mission, you can't go backstage in a theater unless you have a worker's costume. You must wait until a worker goes into an isolated area, take him out, steal his costume, and hide his body. You have to be careful of where you hide bodies, as well; somewhere with a lid like a garbage bin or a meat locker is generally safe, but simply putting one into a bathroom stall will usually result in it being discovered.
You have a variety of tools to help in your assassinations. The most basic and silent weapon is the fiber wire; sneak up behind a victim and choke him without making any noise or leaving any blood. There are a variety of firearms, ranging from pistols to submachine guns to rifles. Besides traditional stats like rate-of-fire and accuracy, Hitman's firearms also have different levels of how well they can be concealed. For example, pistols can be hidden in your clothes, as well as a variety of carried containers like trays, boxes, and briefcases. If you go through a checkpoint, your clothes will be scanned, but not carried items. This allows you to bring certain weapons through checkpoints. Submachine guns can be concealed in clothes, but not in boxes. Rifles and shotguns cannot be concealed at all. The sniper rifle is a special case; it is disassembled in a case by default, is put together when 47 needs to shoot, and can be taken back apart and put back into the case when your shots are taken.
Agent 47 also has poison syringes that can be used on people or on food items (to poison people who eat it). Finally, 47 has small multi-purpose explosives that can be attached to certain objects, placed in containers, or just left out in the open. These explosives are remote-detonated, but the detonator has a certain range. Every weapon in the game can be upgraded with various scopes, silencers, and ammunition types, allowing you to customize your weapons to your playing style.
The gameplay in Blood Money rewards stealth highly. The AI increases noticeably with the difficulty, and despite patrolling predetermined routes for the most part, they will notice discrepancies and problems with a reasonable amount of accuracy. Things like blood stains, bodies, and suspicious noises will cause enemies to be more suspicious and more alert. Even civilians are obstacles, as a civilian who sees you doing something suspicious or illegal will go and report you to the police. In each mission, there's always at least one "stealthy" way of killing off a target with little to no suspicion. Whether it's a series of disguises that grant you access to the target's inner sanctum, where you can sneak up on him and push him off his balcony, or a discreet poisoning of a target's private pot of soup, or replacing a stage gun with a real gun, there's always at least one of dealing with a target that leaves you almost completely free of suspicion. At the end of each mission, the amount of noise you made (how many people saw you kill someone and lived, whether or not you were caught on camera) and the amount of violence used (how many people you killed besides the target, what type of people they were ) is added up for a "notoriety rating" - a scale from 1 to 100 that determines how suspicious of you people are. A low notoriety means that you can get away with a lot and not be suspected; a high notoriety means that, by your face alone, people are going to be suspicious of you and sneaking through areas with disguises will be much harder. It's possible to spend money (earned from doing missions) on bribes so that your notoriety rating goes down.
The best part of the gameplay is how open it is. There are always a few ways that things are meant to be done, but these are optional. Depending on how you want to play, you can use a huge array of methods to take out a target. Each level really feels like an area full of living, breathing people, instead of an obstacle course that you need to get through. Getting through an area to your target requires good reconnaissance and a sound plan based on observation and timing, and it's really satisfying to see everything come together.
Graphics and sound-wise, Blood Money is slightly dated, but still good. Everything is solid and serves its role; the only thing that's questionable is the physics, as dragging a body (by one of its limbs) usually is messy and awkward and difficult to control. However, in almost every other respect, Blood Money is a technically good game. Combined with its fun gameplay, Blood Money definitely deserves a 9/10.