Wow! Quite possibly the best story ever incorporated into a video game.
Being the spiritual successor to Irrational's last game System Shock 2, Bishock is a first person adventure game in a very minor key. Minor is the dark and moody way. Without giving too much away, because the spoilers really do hurt your overall experiece, all I can say is that the story twists you in ways you wouldn't expect and will love. Having the story take place during 1960 at the bottom of the ocean really does add to a very compelling experiece. I love how the story is displayed through out the use of audio diaries and how distinctive each and every personality is who you hear about. This story is just too good to pass up. One of the shortcomings of the game is that it doesn't include a multiplayer. Being how great the single player is I hate to complaing about this, but I just feel these days the replay value of a game generally comes from a multiplayer exsistence. It took my about 16 hours to beat the game, and will one day replay the experience but just not anytime soon. So I can't say if this game is absolutely a most have these days, but definitely a must play. A must have game has a multiplayer experience this days. Period.
In the end you must play this game. Rent it, borrow it, buy it (if you feel its a good value), and have a blast.