I've kind of had a hard time in finding a key jungler. I currently have Amumu, Singed, Eve, and Riven. None of which are epic in the jungle anymore.
I need to find a jungler for me, and one that kind of fits my play style. Generally I like champions with skillshots and a lot of mobility. I also like higher skill cap champions, just because I tend to get bored with point and click champions.
Here are my current list of champions that I like and own: Ahri, Vayne, Caitlyn, Amumu, Evelynn, Singed, Riven, Orianna, Lux, Teemo(Who doesn't own Teemo?), Blitzcrank, Tristana, Nidalee. Just to give you an idea of my playstyle.