Clg
From the start of his time on clg to the start of this season, I've been rather critical of Huhi. He was very limited in the number of champs where he could perform at the top tier of NA -- much less world's tier quality. He would consistently get manhandled by the enemy mid if not able to get one of his few hard-carry champs. I will be honest, with the way much of clg's season has gone this year, I haven't watched all their games. But from what I have seen and from viewing post-game info on games I haven't watched, it seems that Huhi has really stepped up this year. He is playing solid on many more champs than in the past. He is winning or going even in lane even when given less help than the enemy mid in many matchups where he wouldn't in the past. In clg's losses, he is not usually a major reason they lose; in their wins, he is a major contributor to their success. It's great to see NA players like Huhi stepping up their game so much. Even if you are not a clg fan, you can appreciate Huhi's improvement because it means other teams are challenged more by clg and will be forced to step up their game or at least not win in their sleep (depending on what other team you are talking about). Thus, teams will be better prepared for international competition.
Darshan used to be the splitpush monster of NA. The guy you didn't want to have to 1v1 late game as a toplaner. Then he fell off pretty hard and spent the first part of his time on clg playing teamfight tanks. While he was pretty good on them, he seemed to have lost his split-push/1v1 dominance. This left clg 1-dimensional with a protect Stixxay or lose strategy as their only CONSISTENT hope. Sure you'd get the random aurelion sol game where Huhi could carry, but basically it was Stixxay. This season though, clg finally decided to unleash the beast and get Darshan some carry champ games in addition to his teamfight tank games. While he hasn't been the only toplaner who can effectively play toplane carries and does not play them every other game, he has shown he still has the potential. This is actually critical for clg because it makes enemy teams have to plan for more diverse strategies against clg rather than always being able to just plan for and play a comp to shut down the enemy adc and know they have the game in the bag.
Xmithie has always been a favorite NA jungler of mine. Sure he's not always been the best, but he's almost always been at the top tier for NA. He is the embodiment of a selfless jungler - putting teammates ahead of himself. Where he could play for solo kills and counter-jungling to just snowball himself at the cost of his team facing more ganks without counter-gank pressure to help them, he instead chooses to help his teammates. He doesn't look as amazing as some other junglers on some of the flashier carry junglers, but I think a good chunk of the grief he's gotten on some of those games should really have been directed at his teammates. It's hard to look good on a carry jungler when you are focused, warded out, invaded by multiple enemies, and get no help from your teammates. Luckily xmithie didn't let this (or all the grief casters and fans gave him) stop him from playing carry champs. He's shown some decent improvement on carry junglers and still remains a top tier jungler on more team enabling tanky junglers.
Stixxay and Aphromoo have been overrated for awhile. Can aphro be the best support in NA? When he plays at his peak, yes. But sadly, he also makes some really dumb plays and champ selects too. He's kinda the UOL of NA supports - having the greatest highs, but also some very bad lows. He isn't dominating enemy bot lanes nearly as much as he should be this year. Meanwhile Stixxay hasn't done any better. Sure he's only in his 2nd year, but considering his performance last season and how well he seemed to click with Aphro, more has to be delivered than what he has shown. They are losing lane through some careless and disrespectful plays - both 2v2 and when ganked. I never thought at the start of this season (despite thinking they were overrated last season) that I would be saying clg's improvement largely depends on the bot lane stepping up their game to match their teammates' performances.