A quick glance at my portfolio (here) would reveal that for me at least, the answer is "Yes, Always"
I started on film and moved to digital, and I'm in the camp that thinks post processing, either minor or extreme, is part of the creative process. I recently picked up a 27" Dell Ultrasharp (simply jaw dropping for photo work) and I find myself digging out old pics from the archive and retouching them all over again now I can see things so much better (I had been using 2x17")
I will add an important fact though. I shoot in camera raw. In most cases (for me anyway) images shot in raw require some minor tweaks (unsharp mask or smart sharpen especially). I just tend to be very heavy handed in Photoshop (something I'm working on, since one of the guys I work with now refers to me as "Lens Flare Daz"