I guess I'll start...
I frequently frag our toadstool leather (Sacrophyton sp.) and Xenia elongata and take them in for store credit.
I commonly see all kinds of zoanthus, mushrooms, and star polyps sold as frags at the LFSs around my area. Every now and then, there'll be branching hammer, branching frogspawn, and SPS frags available. We only keep softies and LPS in our reef tank, so I'm not familiar with SPS species names.