My very first was GameFAQs and I still post somewhat regularly, but just on the TV board right now.

After that was Final Fantasy Heaven which closed with the creation of RPG Wars.

When I had enough of that place I moved on to Gamers Forums which sadly closed.

Since then I've just meandered around on other boards not really laying many roots either from closures or inactivity. It doesn't help that I became must less social in general online.