The only time I "cheat" is when I'm bored with a game and dgaf. Like with the BG/IWD line of games, once I've had my fill, why not break it? IWD2 was a good example - you could play through on normal mode, then play through a 2nd time with the same characters but with mob's stats cranked up so a goblin can one-hit you easily. After having just beat the game, having my same group wiped in the starting area made me look up all the strats for the "suggested" group builds (monks lol) and I decided to just edit characters rather than to go back and start a new group from scratch.
While I've seen more than my share of actual hacks, I'd still say that most of the people that get accused of hacking really aren't. When I first started DoD pre-Source I'd /rage and think people were hacking, but after playing for a long time I came to see how people could actually play on that level. I was told that if I ever wanted to dominate that I'd have to practice with the KAR for example, so I forced myself to practice a ton and got to where I could pull off some really nice shots (and get accused of hacking). And I played at a LAN store so I got to see people much better than I was actually play that way w/o hacks at all.
One of our FPS kids at the LAN store would run hacks at home to practice with then come up to the store and annihilate people. Like on the DUST maps, he used hacks to see where he could shoot people through walls legit and practiced using headphones to listen to footsteps and then he'd shoot them through certain wall areas. It was hilarious to see him get accused of hacking when he wasn't, though he'd used hacks to practice. I got really good at using headphones so I cold pop out of nowhere and cap people w/o warning, to the point my friends would /rage and accuse me of a "headphone kill" as if it wasn't legit or something. Ah, memories.
I remember one of our guys was really good at grenades in DoD, back when to "prime" them you had to throw them at the ground, pick them up, and then throw them. He'd do this at a full run out of some spawn areas and he'd throw them blind through certain windows, down alleys, and he'd even make some bank shots off walls and kill people almost every time. It was hilarious to see him throw a grenade, watch it arc through the air, then explode in someone's face at the exact moment they came around a corner. ("omg that's bullshit! fucking grenade hacks" hahaha). We also had a guy that ran with a sniper rifle and played hundreds or possibly thousands of matches w/o scoping even once. He'd clear out entire houses with that damned thing lol and use it like a rifle while bunny-hopping everywhere. I know for a fact that he never hacked but he even got banned from some servers for "hacking".