I'm not really a very comfortable jungler but I'm trying to learn on Jax and Xin as they feel pretty easy, also the occassional eve jungler game if she's not banned.
I feel comfortable as anything else more or less, a few characters that have been strong in the past, and I'm not sure how they're doing now since I don't see them alot is:
Irelia, Jarvan, Leona, Riven, Talon, Shen, Udyr
These are champs I don't own but have the IP to buy and I can't really make my mind up.
Also, if there's any other champs that is particularly strong at "carrying" games atm don't be afraid of mentioning them
I also don't have Kha'zix but he's more or less always banned and now gotten nerfed so I'm not really too much into buying him.