From Halopedia, the Halo wiki
Science, Science Fiction, Astronomy, History etc..
HALF LIFE! + Halo, Mass Effect, Crysis, Deus Ex, Elder Scrolls, Age of Empires, Assassins Creed, Far Cry, Grand Theft Auto, The Last of Us, and Portal
Too many to list.
Accidentally killing myself with a grenade.
HALO 5 GUARDIANS!