I get it now with the fizz jungle lol it can be fun to play and i have even tried it but that was in old s4 jungle.
Right now i own about 35 of the champs that jungle, i dont play them all great but there are a few like Sej, Cho, Trundle that i really have a lot of fun with.
Sej : With the changes to her w i had a look one game, at level 12 and with my jungle item, a warmogs and a half charged RoA i was outputting about 600 damage over 4 seconds with my w, you can literally build her full tank with armor, and mr items that also give the best health stats and literally be chunking the enemy with 800+ damage over 4 seconds after the initial damage from your w plus her slowing with e and then charge with q you tend to stick the the squishies and chunk them real quick.
Cho: another of my favs right now, apart from great sustain and tankyness in the jungle once you hit level 6 your ulti "feast" does 1000 true damage to jungle monsters and minions so you can actually eat the buff or monster before someone has the chance to smite steal it. With the change also to his ult if you do feast on the monster, minion or champion (only 300 true damage at the first level) and it kills them the cooldown is halfed from 80 seconds to 40 seconds with 0 cdr, so basically you can feast on red buff and by the time you walk over to blue buff side it is back up and you can get your 6 stacks in about 3 mins after getting your first one.
Trundle: I love trundle and he is highly underrated in the jungle, you can go tanky as hell or have some fun ad if you get ahead you can go for "Whack a Troll", basically with a BotRK and the devourer jungle item when you put your ice down and have it maxed you see your attack speed go above 2.0, once late game comes you can see it rocket to the max of 2.5 attack speed and with that you can destroy a tower from full health in less than 8 seconds (the amount of time your ice is down for) Oh and did i forget to mention his Q (Chomp)? You can chomp, minions, monsters, champions, towers, inhibs and the nexus while then watching "Whack a Troll" go to town with his club. Finally his ulti just wrecks tanks and makes the squishy carries tanke basically true damage from everyone if you ult them. Trundle can also clear the 6 jungle camps on first run with just the two starting pots no matter which side you start on.
Hope this gives you a bit more help :)