KompoZer | http://www.kompozer.net | FREE
JEdit | http://www.jedit.org | FREE
Amaya | http://www.w3.org/Amaya/ | FREE
NVU | http://net2.com/nvu/ | FREE
Komodo | http://www.activestate.com/komodo_edit/ | FREE
Mac only:
Taco | http://tacosw.com | $24.95 & Demo
Coda | http://www.panic.com/coda/ | $99 & Demo
Espresso | http://macrabbit.com/espresso/ | $79.95 & Demo(?)
BBEdit | http://www.barebones.com/products/bbedit/ | $125 or Demo
PC only:
Notepad++ | http://notepad-plus.sourceforge.net/uk/site.htm | FREE