If they use devourer and stack it fast (and can go tanky too!) they're great. if they abuse black cleaver/youmoos combo, they're great, If they can bully the other jungler, they can be good.
IMO play reksai, nunu, udyr/yi, and wukong. get good at voli (ulting well, throwing the carries, righteous glory/dead mans plate) or get good at xin (auto attack cancel with q, max e for the lower cooldown gap close, build tank, attack speed, or hybrid damage to fit the match) and you're set.
honestly nunu is such a safe pick. buy sighstone and take the other junglers camps and secure objectives easy games. your ult is just a huge zoning tool, your w makes your Carry stronger, and your e screws their carry almost as much as nasus wither.
Disclaimer: the only one of those I play is wukong. Nautilus is love. top, jungle, mid, OR support.
good luck! and remember skill on a particular champ beats playing an "OP" champ poorly.