I have heard that your countertop should match your floor. With white cabinets and white flooring what color should the countertop be?

Please take me off your list. Th anks.

Counters should complement the floor and cabinets. They do not have to match. You can pick out a host of colors that would bring out the kitchen and not make it a hospital.
Most of the time the counter color is picked to bring the floor color up to the wall so it all comes together. In the case of everything being white. Something else may be in order.

Something else might be in order? What do you mean?

Perhaps a total diffrent color that contrasts the white. What color are the appliances Perhaps bring their color to the top. What are you doing with backsplash? What about the color or style of the door handles and drawer pulls. that quite often changes how the kitchen looks. If there is color in the handles perhaps bring that to the counter.
What style are the cabinets? Uro, without face frame? Colonial, flush fronts raised fronts? The style of the cabinets will also help determine what you should be using. Perhaps a butcher block look?
You can always use white, with a contrasting backsplash.

This is very helpful. My cabinets are white with flat fronts. I am now looking for new handles. What would you recommend with plain boring flat fronts cabinets. The appliances are white, but I am planning to buy a new Stainless steel sink with my new coutertop. I have a backsplash now that is white with a dark purple (maurourn) stipe in the center. The countertop is that color and it is out dated. Thanks for your advice.