Some more options:
MSYS: a Minimal SYStem providing a POSIX compatible Bourne shell environment, with a small collection of UNIX command line tools. Primarily developed as a means to execute the configure scripts and Makefiles used to build Open Source software, but also useful as a general purpose command line interface to replace Windows cmd.exe.
GNU utilities for Win32: ports of common GNU utilities to native Win32. In this context, native means the executables do only depend on the Microsoft C-runtime (msvcrt.dll) and not an emulation layer like that provided by Cygwin tools.
