Google Maps Fast, accurate, detailed - blows Mapquest off the, er, map. I love the level of detail, it even has the names of every lake in my neighborhood. Just for yuks I asked it to map my route to Frederick, MD (MDS&W on the brain, I have) and it took about two seconds and was dead-on, didn't take me around the long way like Mapquest often does.
Thanks to Rachael for pointing that out. I'm as jazzed as she is with this new toy! Geeks R Us.