Directory Opus and CygnusEd...those were the tools I used most on my Amiga's. Actually, I have switched between all existing models at some point in time (except the A3000 and A4000).
My latest was an A1200 which I stripped out of it original casing and put it into a high tower PC case, together with a hard drive (1GByte!), 68030 (50MHz), 18Mbyte RAM (2MByte internal with a 16MByte SIMM module on my Blizzard expansion) and rewired keyboard controller for a A2000 keyboard.
And I'll bet the thing would still boot if I could turn it on today...but alas, several thousands of miles are between my personae and that Amiga.