Alright, as I've been working I've moved from Micron Pens, to pure brush work, to washes with some impressionistic brush marks, to the inevitable combination of all of them.
However, I love love love forever and ever love Brush Pens. I can put a faster line down with them and their portability gives me a really flexible work area (bars, friends houses, in front of my TV, my desk, etc...). That being said, I've been using the Faber-Castell brush pens for a while, but the tips don't last that long and after a while, the ink in the pen breaks down really quickly.
Any recommendations out there on some solid, possibly refillable, brush pens? What tools can't you live without?