ViaMichelin

I simply adore Viamichellin.com. I travel a lot due to my business and it really helps to calculate both time travel and costs I'll have. Another great thing about it is that it can also provide information about the weather and hotels along the way so i don't have to do a separate search. Sometimes I use it just to plan a short vacation, I add places I want to visit in "via" section and voilà the perfect vacation is planned in a second:)
I can't give it less than 5 stars!