My favorite burst junglers would be:
Excellent early-mid game burst ganks E>Q>R>W proc will usually burst someone down to about 30%, so if your lane is already harassing them, he can secure kills with ease.
has excellent level 6 burst ganks, especially if you get an early Rylai's before tanking up (or even play him AP entirely).
if you build him AD he actually has a ton of burst, especially post 6.
has great early-mid game burst, and reliable ganks.
very high risk/high reward, but if you go balls to the wall full assassin on him, he can annihilate any squishy in the blink of an eye.
extremely bursty with Warrior+Trinity force.
extreme burst, but slightly delayed because it is connected to an execute. If you get on top of someone and have a lot of HP, your bite will easily deal 1300 damage to a low health squishy, and your AS steroid+R makes you quite a scary jungler.
Very bursty all game long starting at level 3. Your E+Q+R can pop most squishier easily, and you can build him almost like a full assassin and capitalize on his massive AD scalings.