PSA: If your jungler isn't a powerful ganker, DONT PUSH YOUR LANE SO HARD
There are many different junglers in this game, some of which can easily gank at level 2-3 and others who struggle to gank until after level 6, or until they have enough damage to burst the target. If you are playing a champion that does not A) provide hard cc or B) have enough damage to kill your opponent before they can reach their tower, don't push your lane. Every time you push your lane past the midline, you open yourself up for a gank from the opposing jungler. If you are playing against a lee sin, expect him to gank early. Find out which side he is starting on and ward the opposite side (usually they go red-blue) then gank.
Don't expect a Shyvana jungle to gank if you are pushed up and don't get mad at your jungler when you pushed the lane and are severely punished by a gank. Play around your jungler and the enemy jungler. Too many games I see either mid or top push their lane very hard and get ganked very early. Know your opponent's jungler. If they have hard gap close with high damage, DO NOT push. Your Shyvana will be a tough nut to crack when she gets farmed and starts engaging mid to late game if you give her the chance. Don't force a champion to play a role they were not intended to play.
That is all.
-Jungle Main
EDIT: I suppose I wasn't terribly clear. There are champions whose identity revolves around pushing mid really hard and then roaming. They can do this quickly and effectively so that the jungler does not have much of a chance to gank them. There is also the case of shoving your lane right before you are about to back or right after your opponent backs so as to deny them CS and force your wave to bounce off of their turret.
I was referring to the standard lane where neither champion benefits from shoving the lane for prolonged periods of time when the gank threat is high, especially given the current meta of high-impact, heavy hitting, ganking junglers. To those saying that picking anything but a ganking jungler is asking to lose the game, I disagree, and argue the notion that your team can increase their chances of winning significantly if they play around their jungler's strengths and weaknesses, and don't just assume that the game is lost because they have low impact early game.
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is one of my favorites, and while she's strong IN a gank, i cant gank a lane without the laner having hard CC or the other laner being pushed up real far.
I've enjoyed playing this fucker more jungle then mid, and boy does he not love ganking pre six. His early clears leave him fairly low, and I just cant gank like a lee sin. Some junglers cant just sit in your lane, and need time to farm or do their own thing.

You missed a few.
Also I feel a few others are pretty damn good and have seen pro play recently as well.


for more vision.
Kill schuttles for vision as well.
Invade, take his camps and find out where the enemy jungler is so your laners can avoid him.
(old)
it tilts me so hard when the laners say OMG NO JG GANKS REPORTED when they should know I cant gank until lv6