For the purposes of this discussion, it doesn't matter whether the pianist is the leader or not -- as long as the pianist plays a prominent role.
For example, my list includes an album by the Mads Vinding Trio, Open Minds, that features pianist Jean-Michel Pilc in a sideman role.
Similarly, Ethan Iverson selected Miles' Round About Midnight as his album to represent Red Garland.
So there's no need to restrict your choices to pianists who happen to be leaders or co-leaders.