The Y Piano is a personal favorite. Greg Sullivan sampled roughly every 4 notes and 4 velocity layers on this piano. Just about every pop and rock act in the mid-70s and 80s seemed to have one on stage as it was the closest you could get to a full Grand Piano without breaking the backs of a roadie army.
The H Planet S Piano has a unique sound thanks to its Sticky Reeds. The H is sampled roughly every 4 notes in two velocity layers. The H was on stage for many rock concerts for decades as it was portable and relatively inexpensive. Script and Shell by Mickaël Ménager.
The W Piano is one of the legendary instruments in modern music history. This piano is sampled at roughly every 6 notes in two velocity layers. The W samples are cited as a particular favorite of Tomislav Zlatic of the excellent Bedroom Producer's Blog.