I usually don't cheat in PvP/MMO/Any Multiplayer Games. If the game is Co-op/Singleplayer, then I usually would play with cheats.
It also depends on just how much I love the game and how much grinding there is. If it's something I can feasibly do by trials and errors, then I don't use any cheats. If it's extremely infuriating, then... Well, yeah, I cheat.