If I had unlimited money I would get a bike like these BMW Adventure bikes. This vid gives you a good idea of what it is like to take these monsters off-road and ride them the way they were designed. Watch for the drifting near the end of the video. That is seriously hard on a bike that size.
I'm pretty sure that these BMW GS 1200s are the bikes that Ewan McGregor and Charlie Boorman use when they go around the world. Awesome series btw.
via Scooter in the Sticks