TOD
Piano, since I could toddle over to it and reach the keys. And organ, on which I took lessons for several years as a kid (from good teachers on good pipe organs), but that eventually gave way to concentrating on piano and other activities. (I've never played it as an adult, but it would be great fun to sit at one and see what the hell I could possibly play on it now. I'm afraid it would be a little like "remembering how to fly" a Cessna, but then climbing into a cockpit of a 747 and trying to fly that.) In school, enjoyed playing some harpsichord in chamber music, but without any formal instruction on it. Celesta in the orchestra, etc.
In high school I got interested in drums from a musical theeder standpoint, got a cheap set and took lessons for a while, and faked my way through a couple of shows. I remember Carnival was one of them. Borrowed a flute and "taught myself" (ha) how to basically get around that, and even the piccolo briefly, and I took one semester of flute lessons. These would be the only things worth even mentioning. I never picked up a guitar, for instance, and anything else I did pick up for a moment, it was just that: a moment.