WinUAE - surely i'm allowed this!!!
Agent Ransack - allows to search through txt files, great for checking off amiga games
Adfview - view/manage the contents of an ADF
Zone Alarm - Firewall
TimeLeft - really handy for Ebay
Protracker - erm... need i say more
TetraCopy - copy a floppy disk and play tetris while you wait
-strangley i didn't use too much FREE Amiga software