What constitutes a heel is open for interpretation. Some of these guys may be considered tweeners(vs true heels). Also, some guys are great heels for only a year or two(e.g. Mach), and comparing them to guys who were lifelong good heels is almost apples and oranges.
That said, I went Piper, Jake, Hollywood Hogan, and Flair. Though there's probably about a dozen workers you could make a case for being on the list.
On a side note, I was hesitant to submit a list devoid of any monster heels. Vader doesn't quite belong. Taker was a good monster heel, but most of his legacy is born out of his work as a face. Andre, Sid, and Yoko should all be options if Vader is as well. Austin could arguable be on there as well(his heel work is what catapulted him to prominence IMO).
