How about the ones that teach you "how to cheat" in [insert game here] by giving you uninstallation instructions? Or, some of them even go so far as to try making you do damage to your OS installation.

I'm sure that joke was funny for like, all of two weeks in 2008, but the Steam community guides have clearly not moved on to a new joke since, and it's... kind of sad? Surely people can make better gag guides than this, but I haven't seen an original one in ages. And it's not like this is even effective at hindering actual cheaters, either, as long as they know how to use Google. It's just lame and unfunny.