I have primarily been a theater techie over the years myself, between that and being a music techie too. Although I like doing sound a lot, I have gotten really interested in lighting lately. To me, the lighting side of things is a bit more artistic and gives me a chance to be a bit more creative. With theater lighting, One can work with all sorts of different colors, angles, brightnesses, etc...there is so much to do! I have always loved the buzz and excitement of creating scenes and such with the lights and then watching it come to life on the stage
Now, don't get me wrong, the sound aspect is pretty neat too. I have always had a good ear for mixing sound and setting up systems, as it is my day to day job, not as much in theaters, but in many other venues.