Icon previewer

Does anyone have any recommendations for Icon Previewers?
I'm currently using "Scott's Glyph Viewer", but it has some issues that
make it painful. It is though good in that it will give you a screenfull.

My ideal would have some sort of categorisation, and know about the common
icon collections and their sizes so I could say "show me icons that I have
both 16x16 and 24x24" for example. But gathering a list of potential tools
would be good. Any suggestions?

/Matthew Jones/
.