||03-09-2012 09:17 AM
Irelia, Pantheon, and Talon are all somewhat poor jungle picks. They do much better in the lane than in the jungle, partly because all three of them have fairly slow clear times.
Of the rest, if you're looking purely at clearing speed, Nocturne is the best while Lee Sin and Xin Zhao clear the jungle at about the same speed (which is still fairly close to Nocturne's speed, maybe 5-10 seconds slower). However, in overall general power, the order is Lee Sin, Nocturne, Xin Zhao. Just something to think about.
Also, as others have said, the top 3 clear times for junglers go to Dr. Mundo, Shyvana, and Phoenix Udyr in that order. Others that are faster than Nocturne include Maokai, Skarner, Olaf, and a few niche/odd picks like Cassiopeia, Karthus, and Malzahar. As you can probably tell from the list, jungle speed is largely determined by how strong their AoE damage is. Anyway, if pure clearing speed is what you want, Dr. Mundo is the way to go.