The reason why i liked Bioshock was the environment you were in, an underwater city named Rapture in the 40's-50's and the enemies you fought were awesome in a creepy/spooky way. Also the amount of exploration and how you could just branch off, look for power-ups, and money. The powers were cool and the gun upgrades were awesome, was like steam punk looking. Also for the fact its not just run and gun but more like a survival/horror game, It had one of the most powerful atmosphere's in pretty much any game ever and is a master of diabolical mental manipulation. The big 'reveal' is probably the most memorable dialog in any game released thus far. great setting, spiced-up game play (slinging bees and hot Tommy-gun lead into the rabbit-masked faces of some of the most dapper enemies I've seen in games...and gigantic drill robots to boot, what's not to like), a story that kept me wanting to play to find out what happened next (as well as the fun I was having) and nothing but sheer polish and care in the areas of atmosphere, music, style, writing and voice-acting. my steam id for some reason is not working thru this site so here it is if i do win, sorry for the inconvenience.
http://steamcommunity.com/profiles/76561198034705819/