My favorite tiny brushes are Winsor & Newton sizes 00 and 000, and Raphael 8404 6/0.
The Raphael is much, much finer than anything produced by W&N. I think that if you are painting teeny tiny things, the 000 size of W&N is a little hard to use, because the proportionate length of the bristle is small, making the distance from belly to the point short.
In a way, it's a little like that Games & Gear brush (though not as bad). The problem is, if you press a tiny bit too hard or if the brush has slightly too much water (a fraction of a drop) or if the paint is too diluted, WOOSH, you have a mess.
Another worthy brush is the Tamiya Pro series, another Kolinsky brush. It is very expensive, but comes with a nice handle, and is very good for precision work.
@Minimachine -- I am not really fond of the brushes that advertise 20/0. Generally, these brushes have tiny ferules and hardly any bristles, meaning they don't carry much paint. The Raphael 6/0 is just as fine as the 20/0 brushes, yet it has a little bit of a belly. The leftmost one:
Now, all this being said, I did most of my freehand a long time ago, mostly for banners, back in the day before sculpted banners, and almost all of it was done with crappy $5 synthetic hobby brushes
Dark Angels 4th Company (3,830pts) 950pts fully painted
