Lets talk about our Favorite Underrated Champions!
Lets see, I only have 3 people that I main who i think are underrated/I've never seen anyone else play.
Zilean Support 
----- His ult is the ultimate bane of bot lane, especially if they dive and forget about it. Most games I've won with him because they underestimate his powerful ult, and his Q bombs.
Veigar Mid 
-------- Used to main Veigar post his Health ult change from the AP change, and now he's extremely powerful against everyone. At a point, he can 1 combo anyone, and if you dare let him go late game, he can use only Q and W and murder anyone even tanks.
Rek'sai Jungle 
-------- People didn't like all her nerfs, but I still find her very viable. Her ult is the best splitpushing and ganking ever! I love to place my tunnels when my top or bot have pushed far so they don't see me, then when they're ganked, I ult in and we get 2 or 3 kills! Same for top, right placement and SUPRISE! Lee sins, Kha's, Rengar's, they don't have enough damage output on me to kill me and they usually run from me <3
This is only my list so yours might be completely different, tell me about it!
is my go-to mid laner when I get stuck with that role. Why worry about trading, positioning, harassing, etc. when you can just farm with Q from a mile away and scale into late game. He's extremely safe despite his lack of mobility, provided you can manage the wave properly.
funniest champ in the game and so unique but no one ever really talks about him after his w nerf.
- Personally I find him sleeper op, if you don't go warrior enchantment ghost on him. Always seems to be an easy win when I play him but I can never get motivated to for some reason. I really enjoy him too.
- I've seen so many carry or bring back games off good ultimates. They're honestly not bad when vi, lee, and hecarim are banned, just they require smarter thinking than when they could mindlessly walk into your jungle level 2 before. I don't have much trouble with their weaknesses right now and their strengths are still pretty good. I'd get scared like preseason6 if they got buffed again.
can be pretty strong and not nearly enough people play her. Runic Echoes and Rylai's are really the only things Eve needs to get going. She's also an expert at chasing down kills
will never not be strong. I'm not sure if she's underrated, but I still don't see her very often and she's one of my go-to mid laners
for obvious reasons
are on the table.
mid. I rarely ever see him and if I do its as a support.
!
and 
(kench i play as support.)