I set up my mother's laptop with Ubuntu and she is perfectly happy with it. It stopped the constant cycle of viruses/spyware I was having to fix, and everything works just the same as far as she's concerned.
Yeah, its helped alot with my family's computers a lot too. (on a side note) I will say im amazed that with one installation of win 7 pro (since rcm version), I havent had any virus/spyware problems (with no anti-virus/spyware software)