Used to play A LOT of LoL.
That's pretty much it unless you count MMOs with a competitive component.
Lead plenty of guilds in War of Emperium, which is a weekly event in Ragnarok Online.
It's a server wide guild vs. guild PVP where you fight over the ownership of castles, which were physical battlegrounds in the world you had to force your way into and past 50-150 players who were defending it, to the heart of the castle and destroy their 'Emperium' which was a massive golden crystal. For 2 hours straight. Whoever takes one, will have to defend it against opposing groups, many times your number. Or y'know, lose it right away. So you had to make clever use of your castle's layout and every guildmates special abilities to make sure you got an upper hand.
It was pretty sweet for the time, and even today (because the MMO genre at large only declines with the years). If you held a castle when WoE ended, it was yours to keep until the next WoE. A whole flippin' castle.
You could invest into your castle and hire guards to help and there was even castle dungeons filled with rare monsters and everything. And a castle treasury with daily treasure chests for the Guild Leader to pop open with lots of goodies to either keep (douche) or share with his guild mates (respect).
I MISS THE GAME SO DAMN MUCH
