Bioshock is my no.1 favorite game ever  made. 

No other game has ever made me want to delve deeper into the history of a game than this one.  It is truly the master of macabre set pieces and tells an excellent story through the lost souls and audio recordings left behind from a more prosperous time.

This game has top notch graphics, tight controls, and an excellent Plasmid system of buying and equippping.  Everything is handled smoothly and the enemies are realistic and frightening with their strange deformities.  The boss fights are amazing and frightening and difficult, yet it is all handled smoothly.

The other people, like Dr. Suchong, who you slowly find out about through audio recordings and test subject corpses and the laboratories that you find are filled with awful, revolting information.  Nothing is what it seems to be.

Filled with unexpected plot twists and revelations about yourself, this game is a roller coaster thrill ride that never ends.  The graphics are still great and everything still works like it did when it was first made. 

Four words.  GAME OF THE YEAR.