I had to go with Cactus Jack.
He lived the Cactus role, and you can see tons of evidence of that if you check out the King of the Deathmatch tournament.
The final match between him and Terry Funk was brutal.
Both were cut badly, burned badly, and just plain hurt. It was actually a little hard to watch.
So, I went with Cactus because that role to me, anyways, personifies hard core.
Dude Love was a close second.