I don’t think there’s any particular thing. What I like about engineering is that you get to have some special knowledge and expertise – you know stuff that other people don’t know – and you can use it to help people and make the world a better place. That’s true of other jobs too, but not all jobs.
Such a variety of projects and types of engineering & the chance to move to other areas of engineering if you want to. And you get to work with some of the most amazing, intelligent people in the world – – other engineers! 😛