Ryze was and still is quite an anomaly. Balancing him has proven way too difficult. At first, many years ago, people would just stack defensive items with mana and demolish the opposition with his high damage output that scaled heavily from his mana pool. Riot tried to change him and rework him multiple times, but it proved fatal. He would be quite silent in solo queue and competitive play and then show a surprise appearance in worlds, destroying teams left and right. Riot then nerfed the champion so hard that it seemed that we would never see him in play, but we still do, to this day. Although rarely than before.
One of the original league of legends champions. He was always quite popular and he always had a few players who you had to ban TF against.
When TF is on the enemy team, you cannot ever split push. You can never just “quickly go to a side-lane to farm creeps”. He controls the game and the map very well. He also had quite a few highlight moments during the years of insane backdoor plays. And now, in season 10, he is quite comfortably picked quite often.
Kassadin was one of the most iconic mid laners for a very long time. Not as popular right now, because games, on average, are a lot shorter, but even now, he was picked and played competitively. His potential to carry the team late game with his high mobility, made him a fearsome champion… If you survive the early game. I will leave you with a video, one of the greatest players in the game, coined and known worldwide - the xPeke backdoor.
Since Zed was released in 2012, he developed the game and showed what a high skill-ceiling a champion can actually have in league of legends. Back then he was quite hard to master, as this clip from the legendary Faker vs Ryu will show. He wasn’t played much in 2020 competitively though, just lurking in the shadows to come back.
First place has to be given to Orianna at this point. One of the most solid and common picks from her release in 2011. I doubt there was ever a year she was not seen in competitive play. Looking at this season, over 50 games in Summer regularly split in LCS and LEC by various teams.
A control mage with great versatility and damage. What else to hope for. I will leave you with one of the great plays back in 2013, named “3000 ELO Shockwave”.