dos2unix on SourceForge, which appears to be actively maintained (as of 2015), and has pre-compiled releases for Windows, both 32- and 64-bit. Also includes unix2dos, mac2unix, and unix2mac.
CygUtils from GnuWin32, which are miscellaneous utilities forked from Cygwin, which includes dos2unix as well as several other related utilities. This package is not actively maintained (last update was in 2008).