No, the Wii has built in memory, but it's recommended you get an SD for the Virtual Console games. They barely take space, but it's nice to have it all in one place. SD cards are cheap.
If you ever bought PS1 games off of the PSN, it's basically the same thing. However, the Virtual Console includes NES, SNES, and N64(priced $5, $8, and $10). You can use a credit card(deposits are set to $10, $20, $30, and $50) or a Nintendo $20 prepaid card in stores. Also includes third party console games such as Genesis, Master System, Turbografx 16, Neo Geo, and Commodore 64(don't know the prices, but none are higher than $10.)
Certain games require the use of the Classic Controller(SNES and N64), which is $20 and is used(but not required) for Wii games such as Monster Hunter Tri and Xenoblade.
Read my original story on Fictionpress (Shinigami Twin): http://www.fictionpress.com/s/2996503/1/Shinigami-Twin
As well as my other one (Hell's Punishment): http://www.fictionpress.com/s/3085054/1/Hell-s-Punishment
Nintendo Network ID: kingofe3
