I never watched those streams too religiously but I did enjoy how helpful they were. Most streamers now-days aren't incredibly helpful and just feed off of their personalities to attract viewers. This isn't necessarily a bad thing, but I like watching streams to see how pros play my favorite champs to the highest level and a lot of streamers don't really bother explaining what they're doing anymore.
As for my current go-to's:
Aphro, Bunny - I love playing support and these two are beasts. Both laid back, semi-informative streams.
Qt / AnnieBot / Dom / Dyrus - I love this group, they're so lax. I know qt is kind of over the top but this guy is a fucking monster at the game and plays it off everytime, one of the few personality based streamers I really really like.