I can say that my D-Link DIR-628 can do it. It is in the PC Room located on th2 2nd floor. It can reach the Wii in the living room on the first floor with over 85% signal strength. It can reach into the basement with over 75% signal strength. It is good enough that i can even go into my neighbors house, in their kitchen and still get 25% signal strength.
So this thing can cover some ground and it has not only 2.4GHz band but 5GHz as well.