What do you do? I'm a web developer and freelance technology writer.
When did you start using BBEdit? I think I started using it around 1993, but it may have been even earlier thanks to some floppy disks I got from a Mac user group meeting.
What's your favorite project that BBEdit has helped bring to life? Every day at every real job I've had from the day I graduated school, I've been in front of a Mac typing text and code into BBEdit. The same goes for any programming or writing project I've done at home. So if there's anything cool, important, or fun I've ever done in my life (a Mac OS X review for Ars Technica, a Perl module on CPAN, a small Unix utility) it was done with BBEdit. And I'm writing this in BBEdit right now, of course.
Which feature is your favorite? My all-time favorite feature is probably single- and multi-file search and replace using regular expressions. There are text editors that expose the full power of regular expressions to users, and there are text editors that provide a nice user interface for initiating searches and seeing the results. BBEdit is rare in that it provides both, and has done so for years. An honorable mention goes to the Process Lines and Sort Lines family of features, which are closely related to search. Thanks to these features and a set of custom key bindings, I can process text faster with BBEdit than I can using pipelined Unix command-line tools. Coming from a longtime Unix nerd like me, that's high praise.