What are so.e good private tour option s at Versailles?
We are using Art Journey for a private tour of Versailles in June. Since I haven't been yet I can't personally vouch for how good it is. However, my sister used this guide last year for a private tour of Notre Dame and the Louvre and she highly recommended him. The website is: http://artjourneyparis.com/
It depends what you mean by a private tour, but if you don't want to spend a lot and you do want an "insider" experience away from the madding crowd, the "guided tour" is what I'd recommend. On the official Versailles website choose "Guided Tours" http://en.chateauversailles.fr/
Be aware that "Except if otherwise indicated, the meeting point for guided tours is at the welcome desk is in the North Ministers’ Wing" -- it is NOT the main entrance where you go through airport-style security. It is across the big cobblestoned courtyard from same. We went through security thinking we could connect back to the meeting point, and found out that is not possible. We had to persuade a guard to let us out through a back exit and "swim upstream" against the crowd to get out to the courtyard!