My wife’s aunt’s computer was always getting full of viruses.  I’d spend a few hours every time I came to visit removing the viruses and get the computer back to a working state.  Sounds like the perfect job for….. Linux!  All she does on her computer is email and watch videos - that’s it.  Plus, I can set everything to Vietnamese for her thanks to Linux’s great internationalization efforts.  Since I wanted a nice, worry-free desktop for her, I installed Ubuntu 8.04.