1. The Grand Opening Spam - During the early days of the site, when it was just first announced on GameFAQs, there was a sort of exploit that allowed you to spam the same message in the amount of times you clicked it. A few days later a 20 second limit was implemented.
2. Forum Grand Opening Spam - Self explanatory.
3. Mmm I'm in my bed by Naked_Mitsuru
4. Akechi RP (troll did by my friends and even me) - A bunch of posts about asking for Akechi RP were spammed in the Poll and Forums.