Hadlee (after he compromised initial pace, became more accurate, and finally a champion bowler in the process), Walsh, McGrath, Vaas and now Gul are five of my favorite bowlers, but that has more to do with their artfully intelligent scripting than raw-n-steady nastiness. Facing any one of the ones in that XI must be/have been like facing a firing squad with a wooden spoon. That being said, the five guys in this post also bowled more than their fair share of nasty deliveries
I'd love to see Malinga play tests again.