BioShock vs Thief 3: Deadly Shadows
BioShock
BioShock is one of the most highly acclaimed steampunk-themed shooters that has a very interesting twist - your very character's DNA can be modified through the use of a selection of plasmids and a special resource called ADAM, allowing you to have superhuman abilities which will serve you well, sometimes more so than the weapon you wield, in your adventure through the fallen underwater city of Rapture. Aside from the many violent mad men (a.k.a. Splicers), the game also provides players with challeging encounters with the iconic Big Daddies and Little Sisters.When it comes to non-military-styled shooters with an intensely immersive storyline, BioShock is among the handful of the "best of the best" (which includes the Fallout series, the Borderlands series, the Deus Ex series and others). The game boasts of having a rather dark storyline that actually challenges you to think about it in a more in-depth way; to link all the clues together to get the complete narrative that is surprisingly a lot more engaging that you'd expect.
2K Games has just released the remastered version of the very first Bioshock last year and if you can get it on Steam, you really should. The very unique experience it can offer you is very well worth the cost.
Thief 3: Deadly Shadows
Thief 3: Deadly Shadows is the third installment of the popular, stealth-based action-adventure game, Thief, where you play as Garrett, the master thief that is rarely seen and never caught. With a large arsenal of thieves' tools to use, clever AI that will act on their suspicions and track evidence as well as fun, non-linear ways to approach an objective, the gameplay itself is incredible, as you might expect. And of course, you'll need to use whatever means necessary to sneak around, steal for the rich to line your own pockets and do other thief stuff. However, fate apparently has other plans for you and for Garrett...That being said, the Steam version of the game seem to be riddled with plenty of game-breaking bugs, making the game hardly playable even to the most ardent of fans. So, if you can get a CD copy of the game, then by all means... after all, it's a great game. But if Steam's the only choice for you, then you might want to just save up and buy something else instead.