I use to be a big fan of notepad. That's right, notepad. It was simple. Then I was introduced to UltraEdit which quickly grew on me. I had seen some other editors like
Scintilla/ScITE but I really like the tabbed interface, macros, etc.. of UltraEdit.
Because I don't have much time to play with different editors, I didn't immediately switch to Scintilla even though I like many things about it.
Then I found this post which made me realize that it can do many things that UltraEdit does.
So I'm using ScITE now but one of the main things I missed from UltraEdit was its context menu integration. I can right-click on various files from explorer and open then in ultraedit, modify then quit. So after some googling, I found the following which now satisfies my initial reservations to switch:
This is a installation that has the context menu handler pre-packaged for easy install. (I'm using this one)
SciTE - Scintilla Text Editor
Separate Dll but I'm sure works just as well (i.e.: I haven't tried it)
Spacedblue | Code: Context Menu Extension for SciTE
Now I admit most developers have a passion for the one they current use, which is mainly due to familiarity, but if your interested then I recommend this one.