Selecting isolated polygons which are not donuts but may overlap using ArcGIS Desktop?

I'm exploring a few different options for this process and I'm unsure what would be most effective. I'm trying to find all isolated, non-intercepting polygons in the same layer (not to merge). Most share boundaries, and a few overlap. Area varies so it unfortunately cannot be the deciding factor for selection (e.g. selecting by max area). I'm using ArcMap 9.3.1.

I created a 10 meter buffer around the polygons, erased the center of my buffer features, then select all polygons that intersect the buffer, thinking I'll just do a switch selection. The problem is that all polygons get selected, I guess because the selection is too tolerant. I don't want merely tangent/touching boundaries, I need them to overlap within the buffer (in effect, avoiding selection of those polygons each buffered feature is created from). The "are within" of course selected nothing. I wonder if dissolve can be used.

edit: as per request, here's a pic representing what I mean by isolated - no other polygons border it from any side.