I've always loved black, white and yellow together. Even if you live in the country, this 'Cityscape' shower curtain from CB2 would add pizazz to any bathroom. It's so fun, plus it's an affordable $39.95. The matching fluffy yellow 'Cirrus' rug is $19.95.
The curtain is made of off-white canvas and comes equipped with power grommets in rustproof brass. It's also machine washable, which is crucial.
I think this would look great with other colors too, like red or brown. Check out the entire 'Manhattan View' collection (top picture) here.