mingw-w64

GCC for Windows 64 & 32 bits

Everything Else

TBD

old

Rubenvb toolchains

Rubenvb has built a number of toolchains including some for less common setups. They are split into two categories: toolchains targeting Win32 or Win64.

OpenSUSE

The OpenSUSE Linux distribution also has a large and well-maintained set of packages for cross-compilation.

A very large number of other binaries and sources are hosted in the File Release System on Sourceforge which might have what you are after.