Shaco,Rammus or Panth

I would go with Rammus.

His passive gives him decent AD even if he builds full tank; as well, his abilities scales really nicely with a little AP.

Rammus is one of the most mobile champion in game. You can dish out lane pressure on all your ganks faster than the enemy jungler can keep up. I would go as far as to say that he is probably the best Jungler right now, he certainly has the highest win rate.

Power ball allows Rammus to zip around the map, making up for his sub par clear times by reducing travel time. It can be used to interrupt enemy channels as well, or just to chase someone down.

Defense Ball Curl is probably one of the best abilities at level 1. Due to Rammus's passive, it boosts his AD as well, and the damage that result from it plus the runes can catch your opponents by surprise. At max level with full tank items, unless the enemy AD champion stacked armor pen, they will kill themselves first before they can kill you. (As Rammus and against him, I noticed that the only one who can touch you at this point is an Assassin such as Zed or Yasuo with armor pen, or an bursty APC).

Rammus also has one of two taunts in game, and in my opinion it is the better one. The 2.25 second taunt lasts longer than any other CC and shreds 35% of the enemy's armor. Additionally, it has an 50% up time with full CDR (same applies to W).

In line with the rest of his kit, his ult, Tremors has a brief cool down while loaded with utility. It damages buildings and has an incredible 240% AP scaling. This, coupled with damage from Sunfire cape, Thorn mail, and DBC will wreck any one who decides to focus you.

Pantheon is good early game, but falls off late due to the lack of an powerful ult. While Shaco is mainly for early counter jungling.

I can attest that as long as your team don't feed, you will not lose with a Rammus. Generally, I build Spirit of the Ancient Golem, Mobility boots, Ice Born Gauntlet, Sun Fire Cape, Locket of the Iron Solar or Banshee's Veil if someone already built a locket, and a Randuin's Omen/Thorn Mail/Frozen heart on him.

pantheon for easy mode, shaco for fun and games + high skill cap, rammas if ur serious about trying to get some wins.

a good shaco is terrifying, but most people aren't good at shaco.

Pantheon carried me through silver, for what it's worth. He's a solid jungle, outduels pretty much any jungler (including Lee Sin at every point in the game, hue), and doesn't fall off as hard as people think he does. I'd recommend playing Pantheon (until the crazy jungle changes, at least)

1. shaco i wouldnt recommend shaco since late game hes pretty much useless when seiging or prevent the opponents seige, hes good enough if ur able to counter jg or pick some1 off(which u can only if u ward). most shacos go for that lvl2 cheese, shaco's box does shit ton of dmg, infact more than any other jg at lvl2 and u would probably hav ignite or exhaust so u would probably win at that stage, but if the enemy wer clever, he would save his smite to duel u, so lvl 2 u do 0 dmg without box and u would hav taken ur stealth as the second skill so u do only aa dmg, while the opponent does dmg from aa and abilities. so shaco isnt bad, just that u need more experience to know what to do at anytime of the game. youtube " tekk" hes a shaco main, and he does give u lots of tips(i didnt see any of his shaco plays since i dnt play shaco, but people say he is really good with shaco)

2. pantheon if i would hav to recommend one of these 3, it would b panth, and since he could w to minions now, he has more mobility than ever, ur map pressure is amazing post six. the opponent jg(if hes intelligent) would try to shut you down pre6. ofc he falls of late game, tho not of an issue due to the plays he can make early game(leesin falls off hard late game but people still play him, the trick is to make use of ur early game adv). u dnt c many jg with stuns and immense map pressure(combine elise and nocturne) and moreover u hav a ranged ability too to finish of opponents

3. rammus i would recommend rammus if and only if u play ranked 5s or duo q, since u would probably be building tank items mostly, u would hav to depend on ur adc and apc to dish out dmg, yes, hes a high utility, very tanky and mobile creature, but full tank build dnt win u games in solo q(meaning u cant carry) so overall rammus is more of a supp jg like nunu, but still a great POCKET PICK.

on a final note, if ur planning to buy a jg champ now, dnt do it, bad idea, try out the new SRU and then decide on who to buy, or if u already hav all those 3 and wondering whom to master, then again wait for some more time, updated SRU is right around the corner