fltplan.com is the best,
Two minutes and I have my flight planned, filed, wx brief, navlog and wx/notams printed, Radar reviewed. Route reviewed on Google earth/sectional/low enroute, and flight is put on company's schedule. A FBO brief is faxed to the destination FBO advising services I want, and I print off a passenger briefing card that explains weather at destination, length of flight, and other info I want them to know about. Navlog tells me how much fuel/time I need at different altitudes, so I know what is the most efficient altitude.
Literally all in 2 minutes.
I then receive a text message showing me ATC's planned route (always know what the clearance is before I ask ATC for it.) And if there are any traffic holds in place, or if a reservation is required to land (like Jackson Hole or Bozeman requires sometimes).