Can't decide between these 4 Junglers, Please help!

Have played all of the below and enjoy them all. I am unranked, was silver 5 last season (Climbed out of bronze before s6). I can't decide which one to main, can someone give some insight?

Master Yi - Really enjoy the late game with him. I get sated fairly fast and like his kit. The only downside I notice is my team often gives up if we are behind early and I never get a chance to shine late game.

Amumu - Got Surprise Party Mumu in a mystery skin. I started playing him and really enjoyed ganking and team fighting. Only downside for me is his insane mana usage. I also like how you can carry fights so effectively with his ult and basically make decisions that your team would otherwise ignore.

Lee Sin - I am always told to avoid him cus of his skill cap. However I have a nice win rate with him (Around 50-60%) and enjoy playing him the most on this list. His mechanics are fun and I have practiced him enough to catch people out with my ult 9/10 times. I enjoy his late game combos as well. Normally go Tank sin for plays.

Vi - Really enjoy her kit and play style. Love team fighting with her and ganking. She can carry pretty hard with a few kills and I like that part about her. Normally go tank with tri force and steraks and Warrior enchant.