>>1
Somethingawful and 4chan have not been a "big internet thing". They spawn a lot of irreverent humour and in-jokes popular among a segment of the geek/gamer/otaku crowd, but aren't really that relevant in the big scheme of things on the net. SA was at its cultural influence zenith in 1999-2001 or so, or whenever they were spawning stuff like All Your Base. Gradually they started tightening posting standards, and got a boost in quality but it seems to have hindered their propensity for generating fast-spreading memes and jokes. 4chan has gradually taken over SA's role of being the "center of internet comedy", probably in large part due to lack of moderation and restrictions, as well as many of the early users coming from SA. Memes like rickroll and chocolate rain have spread much farther into the greater non-internet masses than anything SA ever generated. Possibly due to there simply being more internet-literate people around now. YTMND was never all that popular to begin with.

For all the popularity 4chan has gained though, it still pales in alexa ranking when compared to 2channel. It's only now with this anonymous activisim thing that it's starting to reach into the scale of the cultural influence in america and worldwide that 2channel has achieved in Japan.

For proper scale "big internet thing", I think you'd be looking more at something like search engines to portals to Google to blogs to social networking to Youtube+flash video.