Bioshock has it all: A eerily creative environment, weapons that change with the players' experience, and plenty of good writing. The storyline is intriguing, and the characters are eccentric.

PROS: Bioshock not only delivers well as a shooter - but builds on the genre and challenges the conventional weapons and tools used in FPS games. The "plasmids" add a totally new dimension to what is already an entertaining game. Being able to use Telekinesis to throw objects or Fire to incinerate opponents really gives the player options to engage enemies in many ways. 

One of my favorite parts about Bioshock is that the story is truly intriguing. Plenty of twists and turns kept me interested, but the writing wasn't so self indulgent that it became unbelievable. The optional endings also gives players a reason to play thru the game a second time.

CONS: While Bioshock is nearly perfect, I had a few small complaints. The first was that as the main character, you rarely interact with other characters. While the city around you exists (to some extent) and the story leads you to believe "normal" citizens are still in Rapture, you don't meet any. I know, a very small complaint...