Before, I would just listen to whatever was on the radio, but I had a specific love for rock, pop, and orchestral. The oldest stuff I listened to was 80s hair metal.
When I joined, I almost immediately formed a reactionary, blood-curdling distaste for the majority of brony music. Not all, but definitely the vast majority. This soon spread to almost all electronic music (with the exception of ambient sci-fi music. I still adore that shit.), and then eventually to almost all modern music in general (again, though, there are certainly exceptions). Nowadays, about 90% of what I listen to is mid 20th century classics (from the late 30s to early-mid 70s), but with special exemptions given to modern songs that stand out from the crowd.
So, basically Rock, Jazz, Blues, Big Band, Swing, and classic R+B.