Relic

Warhammer 40,000: Space Marine

Warhammer 40,000: Space Marine (also known as WH40k: Space Marine) is a third-person action video game developed by Relic Entertainment and published by THQ. The gameplay experience focuses on a hybrid shooting and melee combat model.

As a Space Marine, you are given enhanced regenerative abilities and an Iron Halo shield. When health gets low, performing sync kills can allow Titus to get a portion of his health back. You are accompanied by Sidonus and Leandros for most of the missions, though in some instances you will have to go on solo missions.

Warhammer 40,000: Dawn of War - Dark Crusade

This game is a standalone expansion for the Warhammer 40,000: Dawn of War RTS series. Players can control one of seven different factions as they seek to destroy each other on the planet Kronus. The expansion adds two new factions to the series with the Tau Empire and the Necrons. It's an RTS, what more can I say?

Company of Heroes

Company of Heroes is WW2 Real Time Strategy game from the development team behind Warhammer 40,000: Dawn of War and Homeworld. It attempts to combine riveting, accessible real-time strategy gameplay with the cinematic sensibilities of World War II movies. The game supports multiplayer games for two to eight players via LAN or internet.

Two subsequent standalone expansion packs (Opposing Fronts and Tales of Valor) are available, and once installed can be accessed through the same in-game menu.

Homeworld 2

Homeworld 2 is the 2nd game in the Series by Relic & Sierra. The Homeworld series is a Scf-Fi space-based RTS. It was (and largely still is) unique in it's integration of easy-to-navigate 3D battles.

Homeworld

The first fully three-dimensional real-time strategy game. Released in 1999.
Other parts of the series are Homeworld: Cataclysm (2000) and Homeworld 2 (2003).