@motoridersd@pug.ninja @scottwillsey BBEdit/TextWrangler is pretty great. TextMate is nice, also. I'm not sure about autosaving tabs, but another option may be TextAdept.
@motoridersd@pug.ninja @robert I think they've since recombined the two softwares, and TextWrangler is now the free version of BBEdit you get once the trial license expires.
@motoridersd@pug.ninja @robert I think that might fit your needs the best. And they've been around since the System 7 days (and maybe earlier); truly a house of great Mac software. (Although I have lately found myself going back to Nova from Panic ... although that's probably a bit heavier than you're looking for.)