Obviously, I only cheat in Single Player games.
Now to qualify this even further, I will only cheat on my second/third playthroughs of a game, i.e. to make it quicker through sections, I've already completed in that manner (i.e. If last time I blasted my way through Typhoon production facility in DE:HR, the second play through I'd Stealth it, the third play through, I'd dick around and potentially use cheats to see if I missed any secrets or easter eggs).
I've always played like this, I would never cheat Sonic games until I had collected all the Emeralds manually, this could get especially frustrating as a kid when I wasn't too good at them, also it goes with my current philosophy... and let me be brutally honest; I suck at videogames, but I love them anyway and since 2004 vowed I would never play them on easy, only on standard difficulty or harder, which has often meant taking longer to complete them as I die time and time again, but the sense of satisfaction at doing something difficult without resorting to cheating to get past it, is immense... at least the first 2 or 3 times... after that, god mode *****, I'm playin' to see what the loot beyond that optional Balrog/Dragon hybrid is.
So for me, cheating is a way to see things in a game, my skill level wouldn't normally allow... but only when I've struggled through it a few times.