[bhickey]

This is worlds better than TfL's route planner. However, it seems to be confused about where King's Cross/St. Pancras is located.

Moreover appears prone to suggesting some peculiar routes: http://bit.ly/qNyvHb

[panacea]

That's not very peculiar though, is it? A short walk and a single direct bus.

On the weekend I prefer to catch buses over the underground (no pun intended) even if it takes a bit longer.

I'm not in a rush and I enjoy the scenery (the front top seat of a double deck bus is a very cheap VIP way to tour London).

I'd probably use that route.