Electronics. I was always drawn to understanding 'how things work', and the answers increasingly relied on knowing things like circuit design, digital microcontrollers, and general electricity fundamentals.

Later I picked up Basic, which was coincidentally used by the Basic Stamp that my school had a few spares of, which led to my software career, but hardware is still taking up my benchspace.

Hackerspaces and working on physical things in general i think brings the social element, especially when someone needs a tool you have and you need something they have ;)