In-Game Music

[Praxil]

I'm just going to quote myself from other forum.

Halo series: CE, 2 (withouth the pop stuff), 3.
Medal of Honor series: Medal of Honor, Underground and Allied Assault.
Command & Conquer series: I love what Frank Klepacki did there. Excluding the Tiberium Wars which has horrible sondtrack. Generals has awesome soundtrack clearly influenced by the Black Hawk Down film.
NHL series: 96-99 PC versions.
Total War series: All of them, except Shogun which is too lazy.
Rainbow Six series: From Raven Shield to Vegas 2 pretty much.
Silent Hunter series: III and 4.
MGS series: Metal Gear Solid, Sons of Liberty, Snake Eater and Guns of the Patriots.
Hitman series: All of them, Kyd is one of my favorite gaming composers.

Emperor: Battle for Dune
Mass Effect
Freedom Fighters
Call of Duty 4
Dead Rising
Universe at War
World of Warcraft
Perfect Dark Zero
Operation Flashpoint
Company of Heroes
Army of Two


And something I probably forgot...

Adding to that mods like Desert Combat, Project Reality and Insurgency. All the Rainbow Six games have good songs and Ghost Recon games too. Splinter Cell games also. Assassin's Creed, Battlefield 2. ... Something more to that list. All are original, none are licensed soundtracks for these games.