Not to mention, every race in the Horde owes the Orcs big time.
Trolls: saved by the Orcs from the Alliance and Murlocs with their Sea witch
Tauren: Saved by the Orcs from the Centaur
Forsaken: Given political shielding to deter the Alliance, even moreso post-wrathgate
Blood Elves: Got to tag along on the Expedition to Outland, also offered a shield against the Alliance, what with Dwarven and Darnassian Spies in Quel'thalas
Goblins: Allowed to turn Azshara into their new home after Mt. Kajaro erupted