GameShark
From Wiki - GameHacking.org
Gameshark is the American brand name of the Action Replay, originally. At that time the GameShark altered memory address to create cheat codes. It was sold in various forms by Interact until their bankruptcy. The name brand was then sold to Mad Catz in January of 2003. After the aquasition Mad Catz continued marketing the brand as a traditional cheat device.
When releasing the Xbox GameShark it was revealed that it would only use "power saves", game saves which give the players advantages such as early access to items found later in games. From then on all GameSharks released after this point have focused on the power saves and left the address altering cheat codes behind.