Syndra: Her 'point and click' ultimate is retarded for the laning phase and picks (tons of damage). And she is very good at moving enemy champions, and setting up your gank for kills with her stun. Gotta handle her balls correctly though.
Cassiopeia: Her E spam deals a ridiculous amount of consistent damage that can catch many people out if you build Rylais since they can't get away; you can punish people heavily for missing their spells since you can't miss yours. Her root is also retarded since it renders a lot of mobile champions (adcs specifically) useless. Her ultimate is also a team fight game changer if you can stun multiple people.
Orianna: Laning phase is extremely easy. You can cs well with this champ even if you're up against a much more skilled player. And her ult is a very linear game changer. Use your ult to get kills, and cs to maximum power.
Aurelion Sol: Requires a good deal of map awareness, you rely heavily on roaming. Snowball your other lanes. Plus your ult provides a lot of safety, assuming you don't miss. Dopa said Aurelion Sol has a broken laning phase. "A bronze player can get out of lane against Challenger if they play Aurelion Sol" He's very hard to run away from as well, like Cass. Damage output is not good imo. Dont really see that many Sol players anymore.
Viktor: ??? Idk. Just does a lot of damage. Wtf.
Bard: Always good. Never bad.
EDIT:
On what
@Astro said:
I guess Zed too. He's super mobile and pokes well. If you play him well, you should almost always win lane. His high single-target damage output makes him good in solo q where there is less organization and less team-oriented gameplay. His roam potential is very good too since it's seldom "too late" for him to walk into another lane. Even if the enemy laners see him coming in, Zed can catch up if they start to back out.
Kennen is just very good late game. Kennen's ult is maybe one of the best teamfight ults rn. He can be played top, mid, and support, just for the value of his mass stun + damage.