Not all are HDR. #4, #6 and #7 aren't.
The trick is simply not to overdrive the effect.
When you look closely, there is always some clipping going on somewhere in the picture - don't be afraid of clipping, it's a natural part of a photo, and trying the work around it by doing extreme HDR work makes it look fake.
I always have the advanced bracket function to take 5 pictures, which thereby covers the entire adjust-range of the camera (-5 to +5). However, I don't use the entire dynamic range that is possible this way. Most of the times, I even threw out most of the exposures and end up only using 2 or so. When doing the editing, I pay attention not to brighten up the darks too much, as well as not darken the brights too much. And, finally: keep the finger from the clarity!
Cranking up these three, basic parameters give this "radioactive vomit" look HDR often is associated with.
Of course, there are other parameters that play a role here. Those who are familiar with tonemapping are aware of, that there dozens of them.
Software wise I use Photmatrix most of the times, but for the merging only! The rest, and most of the stuff, is done in Lightroom.
This is at least my workflow, and I'm sure there are tons of others that work fine as well.
