Well, it turns out I'm not remotely correct abut that. There are the four that we've always heard of: solids, liquids, gasses, and plasma. There are also superfluids and super-solids. Plasmas are a sort of "class" of states of matter, including typical plasmas and quark-gluon plasmas. Then there are the extreme low-temperature states such as Bose-Einstein Condensates, Quantum Hall states and the so-called strange matter.
I bring up this rather non-exhaustive list to make a point. We really don't know anything. Not a thing. And that's fascinating, if only because it means there's always something new to learn, even about something we always used to say was "basic" and "certain". How then can you say to be certain?
I ask questions because I don't know. Here's something else I don't know: What do you feel like hearing about over the next week? Well, the ~65% of you who aren't programs hitting the website to spread around your domain names, anyway. I imagine "hitbots" can't leave comments.