PEiD (short for PE iDentifier) is a well-known professional packer/cryptor/compiler detecting tool. It's so powerful that it can detect the types/signatures of almost any PE file packing tools (at present, the number has been more than 600 kinds). In addition to the official version, AppNee also provides you its full-plugin version, which can be treated as the most perfect one version (contains 60+ plugins and necessary runtime library files: mfc70.dll, msvcr70.dll, rtl70.bpl, vcl70.bpl) on the Internet at present. I do believe reverse engineers or software cracking/unpacking enthusiasts must like it very much.
Exeinfo PE is a popular and universal free analyzer & detector to executable files' packer/compressor/compiler, written in Delphi by A.S.L from Poland. It is capable of detecting 300+ binary data types (non EXE formats and more signatures on Ext_detector.dll) with info about how to open them via some free tool.
UPX (Ultimate Packer for eXecutables) is a very comprehensive executable file compressor/decompressor that only supports DOS/command-line. It supports executable files on almost any sorts of platforms (EXE, DLL, OCX, BPL, CPL, etc.), comes with excellent compression ratio.
MoleBox Virtualization Solution (MoleBox VS for short) is a real-time software visualization/distributing tool with not perfect but professional and complete functions. It can package some software on Windows along with all of its auxiliary/necessary data and components into a single executable file (EXE), which can run the same as before or even faster.
UPX (short for Ultimate Packer for eXecutables) is a classic, illustrious universal and extendable lightweight packer for various executable files (such as EXE, DLL). With excellent compression ratio and very fast decompression speed. And can be regarded as a commercial quality freeware!
htm2chm is a very practical CHM file (Microsoft Compiled HTML Help) creator, compiler, editor and decompiler I found a few years ago when searched "convert flash into CHM" in Google. At that time, I wanted to pack a flash file along with its related documents (HTML, TXT, ZIP, etc) as a CHM format e-book, so that I can take it anywhere.