I started a software company back in 1999; we're still around and up to 10 employees, so I have had some moderate success in the software business.
I think the LifeHacker link makes a lot of good points. I especially agree with limiting overtime. I *never* ask my developers to work overtime. Just never. Because I don't set release dates. When someone asks when the next release will be, I say "when it's ready" and I mean it. It's far more important to get it right than to get it out "on time", whatever that is.
I would add that to be a great software developer, you need a lot of discipline. You need to write your unit and regression tests even if you don't feel like it and even if you'd rather be moving on to the next cool feature. You need to write your documentation clearly and comprehensively. You need to have your code reviewed; even the best programmer can benefit from suggestions that improve code clarity.
You need to listen to your customers. You can write the greatest software in the world, but if it doesn't do what your clients want, that's not much use. But you also need to have enough judgement to know when your customers are asking for something ridiculous and you need to have the communication skills necessary to explain to them why what they think they want isn't what they really want.
You also have to be passionate. If you went into computer science because you thought you'd get a secure job, but never particularly liked computers and didn't do programming on your own time, forget it... you won't be a great software developer.