Just a shameless ass-kissing post praising Riot for...
... Final Boss Veigar. Seriously, this is the best skin in the entire game, worth every penny. The skin alone has given me reason to pick up and play Veigar, and it's gone a long way towards helping me improve as a mid laner.
I used to have trouble following my spell rotations as Veigar, because the default particles on his Q and autoattack were so similar it was hard to tell which one landed when, and whether or not I got the last hit with my Q. Final Boss Veigar solves those problems.
Thematically, it's been an absolute joy to have my childhood gaming memories brought back to the surface when he exlaims "Hey, listen!" or "Somebody set up us the BOMB!".
So thanks to Riot for the Final Boss Veigar skin... it's a perfect example of everything a player could want in a high-end skin. Keep up the great work!