Shoto-kan Karate-do. In hindsight, I should have specified!
I looked into Aikido for a bit, a friend of mine was taking classes and showed me some moves. It felt a little awkward to me, but that was after years of karate, so I was far too used to straight-forward moves to really appreciate the more nuanced and subtle art. It's something I regretted and eventually tried some Tai Chi instead. Schedule prevented me from keeping up with it though. Gotta get back onto that, honestly. Some kind of martial art, at least.