Some clever and some I had not heard before. Three examples:
Shaker’s Law of Departure – “Those who egregiously announce their imminent departure from an Internet discussion forum almost never actually leave.”
Shank’s Law – “There is no idea so batshit insane that you can’t find at least one PhD scientist to support it.”
John Gabriel’s Greater Internet Fuckwad Theory – Normal Person + Anonymity + Audience = Total Fuckwad
And one I had and still like:
Brandolini’s Law - "The amount of energy needed to refute bullshit is an order of magnitude larger than to produce it."
I can recommend, "Eponymous Laws Part 3: Miscellaneous," too.