Halo 3, while suffering from a few faults, still manages to be a very fun shooter.
Halo 3 is (obviously) the third title in the series of games that is the Halo trilogy. Having crash landed on earth after the events of the second game, Master Chief (once again) takes up his rifle to fight for humanity's survival against the evangelical cult known as the Covenant.
This is the first flaw I have against Halo 3. Just plainly, the story sucks. I'm sorry, I tried to get into it, I tried to understand the "deep and immerseive" world that Halo fanboys raved about, but I simply did not like it. Other than very few exceptions (like Super Mario Galaxy), I am unable to tolerate games with weak storylines. This is what hampered my progress in Halo 3, because of the uncompelling storyline that gave me absolutely no reason to save Earth.
The gameplay however, is almost top notch. You will experience vicious gunfights against the (surprisingly intelligent) forces of the Covenant and the Flood, as they send wave upon wave after you. I played Halo 3 for the first time on Heroic, so it was a pretty difficult experience. Unless you're the kind of person who playes on Normal or Easy, expect Halo 3 to be a pretty satisfyingly challenging game.
The multiplayer is also very enjoyable. With a variety of new and re-imagined maps, gameplay in multiplayer is always fast, furious, and fun. The new and improved rank and level system also offers quite a bit of replay value to the multiplayer, as one constantly tries to reach the mythic General rank.
Unfortunately, though not a fault of the game itself, the same community that plagued Halo 2 has returned for another round of incessent annoyance in Halo 3. From unbearably high-pitched 10 year old boys attempting to swear with the prepubescent voices to 20-something frats whose vocabulary is limited to "**** you" and "ha ha, ***", expect to be using the Mute option a lot, which is a godsend for gamers like me.
In general, the game also holds A LOT of replay value. From the hidden skulls on each levels to the various unlockable armor, expect to spend a lot of time playing, if you're the sort who needs to find every piece of armor and every hidden skull.
Overall, Halo 3 is not the AAA game that you should expect. If you are like me and put story at a very high place in your priority for a good game, expect to be bored of it very soon. However, if gameplay is what you're looking for, you have an exceptionally fun and entertaining game on your hands. Despite some of the flaws that plague the game, Halo 3 still manages to be a very fun conclusion the Halo trilogy.