http://www.sublimetext.com/ is a good editor for windows, though I think it differs from textmate in a few areas which I think is developed by one person as well
Good suggestion for Windows. One key feature for Sublime Text is the minimap and for those wanting that in TM, Julian Eberius developed a TM plugin - http://julianeberius.github.com/Textmate-Minimap/
The minimap plugin is cool looking, but it totally chokes on large files and I never really used it anyway. It also kind of bugs me that it's in a drawer instead of a pane (which is why I use Missing Drawer for the project pane http://code.google.com/p/textmate-missingdrawer/ )