By popular demand, here are five brushes I've been using recently. None of these are meant for any specific purpose, so I use any of these brushes to do any part of any painting.
By mixing them throughout a project, I get a less smooth, less digital and more cohesive look.
Here's a dropbox link to the file, since some have reported having problems with the dA download [link]
These are meant to be used with a pressure sensitive tablet. They're created in PS CS6, but I think they're compatible with earlier versions!