simtelnet/msdos/disasm/ - DOS based disassemblers. - http://www.simtel.net/category.php?id=73
Phoenix Disassembler - A Win32 PE File Intel 80x86 Disassembler, with API call conversion, and Navigation control. [Freeware] - http://www.minds.nuim.ie/~phoenix/projects.html#disasm
Define - New shareware assembler/disassembler with major differences from those available, by Alan Baylis. Download holds assembled and QBASIC versions. - http://www.alsprogrammingresource.com/define.html
PE Explorer Disassembler - A Windows 32-bit PE file disassembler and file editor, with a strong emphasis on peeking inside Delphi applications and packages. - http://www.heaventools.com/PE_Explorer_disassembler.htm
Xope Systems - Offers Lantern (an advanced interactive decompiling environment in a form of a plug-in for the Interactive Disassembler Pro program) and reverse engineering services for x86 and compatible machine code. - http://xopesystems.com
Hiew - File viewer and disassembler for NE,LE,LX,PE formats and Netware Loadable Modules NLM,DSK,LAN, by Eugene Suslikov. [Shareware] - http://serje.net/sen/#hiew
HT - Is a binary file viewing and editing tool including disassembler for DOS and Windows 16/32 formats (MZ, PE, LE) by Stefan Weyergraf and Sebastian Biallas. [Open source, GPL] - http://hte.sourceforge.net/
Binary Editors for DOS - With disassemblers EDCOM by Doug Cox and HexIt by Mikael Klasson. - http://www.bookcase.com/library/software/msdos.util.binedit.html
Windows CodeBack disassembler - Windows 3.1 Disassembler by Leslie Pusztai Jr. [Shareware] - http://www.winsite.com/bin/Info?500000032266
Nocash HACK Debugger - PC disassembler/debugger by Martin Korth. [Freeware] - http://www.work.de/nocash/hack.htm
BORG - Windows 32-bit PE file disassembler by Cronos. - http://www.caesum.com/
VXDasm - A Visual disassembler for Windows95's VXDs devices drivers, by Jean-Louis Seigne. [Shareware] - http://www.chez.com/jls/vxdasm.html