on emulators, i cheat all the time, but otherwise, i don't. i always find something new when i'm playing my cartridge and am trying to maximize the stats of my pokemon with nutrients. rather cheating to buy them, i just battle trainers who dish off a lot of money with amulet coin. also, cheating to attain pokemon isn't really necessary. the chances are if you're open-minded, than you will definitely find all kinds of good and strong pokemon.
heck, a clefable might not have stats as high as a salamence, but if you train it the right way, it can destroy an in-game salamence.