Would you rather- A. Go into the past and meet your ancestors or B. go into the future and meet your great-great grandchildren?

If we can bring back knowledge capable of changing it ... The future.

Neither.

I'll stay in the present  to build my future.

The future is not yet.

The past gives you real, tangible information.

I'd love to know WTF some of my ancestors could possibly have been drinking.

(I meant to say "thinking," but that's probably why they did most of what they did.)

I'd like to go to the past and meet my father before he went off to fight in WWI. I talk him into staying in Blighty after the war instead of returning to Oz.

That way he would never have met my mother, I'd never have been born, and I wouldn't have had to bust my tiny brain trying to think up an answer for this question.

>;-/

The past, because I have a (very small) chance of meeting my great-great grandchildren.