I've always just used Notetab Light (they also offer a pro version). For HTML and CSS I do most of my coding in Dreamweaver, but for quick one off things when I don't feel like loading up Dreamweaver, I will do it in Notetab. I've been meaning to play around with Adobe Edge Code more though, to see if I would like that or not. I've even used Excel from time to time, when I need to bulk create some large amounts of HTML from a big data set.