Upload & Sell: On
Nik Color Efex Pro 4 and Silver Efex Pro 2 - indispensable tools IMO...they've really transformed how I postprocess my images. The tools there are really wonderful for quickly bringing what I have in my mind as to how to process an image into reality. Unfortunately, they're not cheap, though.
Best thing is that they have filters and such that can really just provide good tweaks to give that great contrast or improve color rendition, as well as more 'artsy' type filters. Silver Efex is used on my end for about 90% of my B&W work, as I get the balance I want easier than most anything else.