Undoubtably the best of the series and by far one of the best games i've played.
GAMEPLAY
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[combat]
GTA IV's combat has been greatly improved from the clunky shooting of it's predecessors. Armed with a refined targeting system, a cover system similar to that of Gears of War and Uncharted and hand to hand combat that seems to be inspired by Assassin's Creed, GTA IV has combat down to a tee.
The targeting system is simple. You pull the left trigger all the way for a lock-on and with little nudges of the right thumb-stick you can aim for specific body parts, and if you let go of the trigger just slightly, you go into free-aim to be even more specific with shots. While in cover (activated by hitting the right shoulder-button) you can also blind-fire which is handy when low on health.
Cover is an extremely handy mechanic and sure beats the crouching behind something from the previous games(all though that is still possible). It's very cool that you can take cover behind anything in your environment and even cooler that most of this cover is dynamic and destructible. If you encounter a foe hiding behind a pallet of cardboard boxes for example, those cardboard boxes can be shot off individually to reach your enemy. When in a heavy firefight, you find yourself looking around your environment looking for the best cover points that can not only provide sufficient protection but that also provides clear shots at the AI (who also use cover).
The hand to hand
[UNFINISHED]