This is more common in console games, since they can't be patched, but another form of cheating is exploiting loopholes that give you extra lives, gold, etc. For example, in MVP Baseball 2004, if you save a season game at the end, but before playoffs, you can save, exit, reload to keep gaining MVP points to unlock extra features. Or, in Link's Awakening DX, theres a hidden dungeon you can exit and re-enter to collect rupees (the game's currency), until you're maxed out.
There's another form of cheating I've come into contact with mainly in fighting games such as Capcom's Street Fighter (or any fighting game for that matter). Some players, mainly unskilled n00bs, will pick a character that's overpowered and whore one move that just happens to go through whatever the other player throws at them.
And finally, the console equivalent of the above mentioned editor, the gameshark, action replay, or any such type of cheat device.