A landmark title in gaming that is not, under any circumstances, to be missed.
Bioshock is easily one of the most impressive games I have ever laid my hands on. From the second you fire the story up it grabs you and drags you into the game world. Rapture is one of the most impressively detailed and beautifully planned game locales I have ever see in my life (and believe me, I have played A LOT of games). It absolutely oozes atmosphere and every corner of the world, no matter how insignificant to the story it may be, is intricately and painstakingly detailed. Of course, if you are just running through the game and not paying attention to anything but your objectives, as I suspect many of the reviewers who dislike the game are, you won't notice it.
You see, Bioshock is not a game that you play for the objectives. Yes, there is a main story, but the beautiful thing is that story is eclipsed by the underlying plot. The main quest is really just an excuse for you to dig deeper and discover what the hell happened in Rapture. It isn't like your average game where there really is no outside story; Bioshock makes you feel like you have stumbled into something that has already happened and that you are just a small player in a large, and, ultimately, far more important game. That is why you never see your character's face or hear his name. The game isn't about him. The game is about Rapture and the implications of what happened there; your character is just a vessel used to explore.
Now that we have that out of the way, I have to start by saying that this game is gorgeous graphically. Anyone that says otherwise is quite simply mistaken. The enviroments are phenomenally detailed, the character models look great, and the effects are among the best out there. The water looks fantastic, the lighting is at times great looking and at others awe inspiring, and the particle effects are nothing if not top-notch. It is, however, true that the game is a little dark. Fortunately, most TVs have brightness adjusters and there is also one in the game, so this is basically a non-issue.
The sound is amazing here as well. Everything from the haunting whispers of insane splicers echoing through watery tunnels to the moans and groans of the massive Big Daddies to the sounds of water flowing and dripping all around you serve to drag you into the game and make you feel as if you are actually there.
Now, for the last thing and then I will shut up, the gameplay. If anyone thinks the gameplay here is repetitive or dull, I would challenge you to provide some ideas on how to improve it. Yes the main mission objectives aren't that exciting, but once again they are only there to give you a means to explore. The combat is amazing, there are literally dozens of ways to deal with any given situation, from throwing a propane tank with your mind to shocking someone so you have time to line up that headshot. You can stack things called tonics to give you new abilities or improve others to suit your personal style and lay out your plasmids of choice to let you deal wtih issues the way you see fit.
Bioshock gives you total freedom to deal with enemies any way you like, and no two people will play the same way. What this means that if the game is getting repetitive for you, you should stop using the same tactic over and over and try something new! The options are there, you just have to take advantage of them to really enjoy them. Add to all this the incredible tension that has you jumping at the drop of a pin and constantly looking over your shoulder, and you have a game that screams next-gen on every front.
I don't mean to sound arrogant, but simply put, if you read a negative review of this game, DON'T BELIEVE IT. This is as close to art as any game ever has been and every gamer who is old enough to play it would be doing themselves a disservice to not add it to their library and treasure it for the classic it will surely be.