I know at one point there was a thread on CS for sharing Miis made or found on Wii during the seventh generation, but I'd figured it's about time I make this thread for those who want to share their Miis for use in other players' Nintendo games via QR codes. Also I didn't want to flood the Tomodachi Life thread with the following 19 QR Codes.
I'm throwing these in spoilers so the first post won't be so large vertically. The following only work in Mii Maker (3DS and Wii U) and Tomodachi Life (3DS):
You can also use my Mii if you want: