Hiew

Hiew (Hacker's view) is a with disassembler, running in text-mode.

and much much more
 * editing files of unlimited length
 * disassembly of NE, LE, LX, PE, and little-endian ELF executable formats; OMF16/32 and COFF libraries and object files
 * Pentium-IV(R) & AMD 3DNow!(R) disassembler & assembler

As of version 7 it's win32-only, unicode-capable and enables use of plugins.