I second the push for scite. I've done a LOT of text editor shopping around, and have grown to hate bulky editors. This thing is fast, light, but feature packed.
It can do RegEx search and replace, autocomplete, Multiple File Search, highlights any language known to man, you can script your own extensions if you feel so inclined. It can run batch files, and other things with key commands (I can compile any project by pressing control+1, then view it with control+2).
Out of the box, the thing is amazing and easy to use... and as you use it more, you can slowly learn the relatively simple customization.
AWESOME EDITOR ...
Note: It isn't as good in linux, or a linux port to mac os X.