I would like to see some more of the more playful or colorful skins again. I completely understand some of this skins might be not match the current theme or style of League of Legends, but you cannot deny some of these "silly" skins already exist too.
Now don't get me wrong, the recent skin work has been out of this world. And as a customer, I think you have created "value" for me; your recent skins are all a huge improvement over the older ones and for (the most part) the same price.
But with all of this fantastic and thematic stuff, what happened to the other stuff like Lil' Slugger Trundle? Or Totally Not Blitzcrank? (Even Pool Party Ziggs?) These serve to lighten the mood and are always good for a laugh or two.
With this in mind, I even have two ideas. One belongs to my friends though.
Batter Jayce / Baseball Jayce - Because I mean, his melee form E really feels like taking a Louisville Slugger to someone. Not to mention his ranged Q's can easily be seen as a fastball. Acceleration Gate? Oh that's just a cheating Technologist!
Bowling Malphite - Lots of potential here. Namely, his Q already looks a bit like a bowling ball. Now imagine the possibilities for his ultimate. Little **STRIKE** animation windows popping up if he knocks-down all 5 enemy members (think of the cute animations on Arcade Sona).
Bonus perks, there's already a few soccer skins (albeit dated) and the aforementioned Baseball Trundle skins -- Maybe even a Baseball Jayce skin for the next All-Star Game or World Series?
Just Another Summoner
P.S. Zyra also needs a Poison Ivy theme skin. I know you guys are huge comic book fans. Also, if anyone else has some ideas on silly (but fitting) skins, please feel free to share! Oh and for the record, I am not even a huge baseball fan. I just recognize the similarities there with Jayce.