I'm a great fan of jazz piano trios, such as the Brad Mehldau Trio with Larry Grenadier and Jorge Rossy or Jeff Ballard, and the classic Bill Evans trio with Scott LaFaro and Paul Motian. But until today, I never realized that the first piano trio I ever got into was not a jazz trio but a rock trio: Emerson, Lake, and Palmer. Consider the piano/bass/drums passages of "Take a Pebble," from their first album:
This was definitely the first such music I ever heard, several years before I got into jazz.
[I was listening to ELP this morning because of this post about ELP by Don Brown.]