The other thing to bear in mind is that some (older) games won't recognise larger cards so you may end up having to buy several cards anyway.
We have a 8GB card that the kids store Wii channels on that works just fine, but Guitar Hero won't recognise it so we have to use a 2GB to store the GH downloadable content (extra songs etc.)
Wii Classic
The original Wii supports GameCube games on disc, and has GameCube controller ports hidden under a plastic door.
Wii Family Edition
There is an "updated" Wii that goes by "Wii Family Edition" on the retail box. It is identical in many ways to the old style Wii, down to the form factor. However, it does not support GameCube discs or controllers.
The best way to tell them apart is the model number - the Family Edition is model number RVL-101, and the "classic" Wii is model number RVL-001. This number is printed on a label on the bottom of the unit when it is in the vertical orientation. If it's lying horizontally, this label is on the right side of the unit when looking at the front.
You can confirm this information on Nintendo's support website. Click to view the Wii manuals, and you'll see two sets, one for the RVL-001, and one for the RVL-101. The 001 manual mentions the GameCube ports, while the 101 does not.
In addition to the model number change, there are a couple of other telltale signs:
- The plastic panel covering the GameCube ports on the Family Edition is screwed down, where on the older model it flipped open. Underneath, the holes are present for the controller ports, but the ports themselves are empty.
- The serial numbers on the "classic" Wii tend to start with L, and the Family Edition serial numbers appear to start with K. However, since serial numbers are at the discretion of the manufacturer, I'd hesitate to act on that information alone.
- The Family Edition Wii doesn't ship with the vertical stand, although since the case design is identical to the previous design it can be used horizontally or vertically.
- The Family Editon's Wii logo is parallel to the disc drive slot, (making it correctly oriented when the unit is horizontal) whereas it was perpendicular to the drive slot on the original Wii.
Wii Mini/Wii U
Since introducing the Family edition, Nintendo has also released the Wii Mini in some markets, which does not support GameCube games at all. It is also missing network support, and has a top-loading disc drive rather than the front-loading drive of the original Wii design. It is essentially a bare-bones, stripped down version of the original Wii.
The new iteration of Nintendo gaming hardware is called the Wii U. Despite similar names, and cross-compatibility with certain Wii peripherals, the new Wii U does not support GameCube discs either.
Best Answer
If the corruption problem was caused by the hardware, then the Wii will still corrupt those specific GameCube memory cards today, as there have not been any substantial hardware changes to the Wii since release - and the hardware changes that have occurred were primarily to prevent hacking the Wii.
If the corruption problem was caused by software, we don't know if it is fixed or not, as Nintendo has never acknowledged the issue, nor specifically said that a new version of the OS has fixed it.
If you are concerned about it, just buy a different card.