Need a couple more GB of space on your hard drive? Check your R3d logs folder.
So I was looking for things to clean of my C: drive since it's just a little 120GB SSD, and I found out that after a year of LoLing on this computer I had built up over 1,400 R3d logs, which was about 2.5 GB total. So uh, if you've been playing League for a while, you might want to check in "C:\Riot Games\League of Legends\Logs\Game - R3d Logs"
(I was using WinDirStat to find the big files/folders on my hard drive, for those who might want to take a closer look.)
Also, if any ritos see this, it would be nice if those R3d logs cleaned themselves up. ;D