Proper

X3: Terran Conflict is the latest appearance in the X-series by Egosoft. This is supposedly the final chapter. It's a space simulator, offering many possibilities to it's players, like fighting, trading, building factories, fleets, etc.

The latest installment in the action/platform Lego series. "Play as Batman and his sidekick Robin as you build, drive, swing and fight your way through Gotham City. Then, jump into the story from the other side and play Batman's foes ! There is no rest for the good (or the evil) !"

FreeSpace 2 is a space shooter from Volition, the sequel to Descent: FreeSpace. FSO is an open-source port of the game that adds tons of new features to the engine like pixel shaders, and more importantly, widescreen support.

Ship Simulator 2008 is a mission-based motorboat simulator which also features free roaming in various locations and weather conditions, multiplayer mode and a mission editor.

A modern re-imaging of the classic NES platformer. A funny little title with a retro feel.

System Shock 2 is a 1999 first-person action role-playing game, designed by Ken Levine for Microsoft Windows. The title is a sequel to the 1994 PC game System Shock, and was co-developed by Irrational Games and Looking Glass Studios. The sequel was originally designed as a standalone title with no relation to System Shock; story changes were made when Electronic Arts—who owned the Shock franchise rights—signed on as publisher.

Thief™ II: The Metal Age gives you a chance to revisit the dark streets of the City, now changed by the Order of Mechanists, a new cult which has embraced many of the followers of the fallen religion of the Hammerites. In a world of steam robots and cameras Garrett will have to face a new opponent - Sheriff Gorman Truart, a lawman determined to rid the City of all criminals, starting with master-thief Garrett.

Stalk your prey on the quest for stolen goods with your blackjack, sword, and an assortment of unique arrows. Steal for money and uncover the hidden agendas of your allies and enemies as you play through an unravelling story of deception and revenge.