NOTE: a native port of the application is available for Linux and MAC!
The IDA Pro Disassembler and Debugger is an interactive, programmable, extendible, multi-processor disassembler hosted on Windows, Linux, or Mac OS X. IDA Pro has become the de-facto standard for the analysis of hostile code, vulnerability research and COTS validation.
Can disassemble many different CPUs (IA-32, PowerPC, JVM, Atmel AVR) and file formats (EXE, DLL, VXD, COFF, ELF, etc).
Available as a free version (older), as a limited trial version and as regular payware.
 Because of an existing native Linux version of IDA Pro, this is only for a reference installations and for test purpose.