If time travel were possible, to what time in the past or future would you go? Also, would you interact with the events around you or not? Rembember that the butterfy effect will be an issue, so don't be surprised if things are different when you return to the present.
Personally, I would go back to the time of the dinosaurs to see what really killed them off. As an INTP, I am an observer not an interactor. Therefore, I wouldn't be interested in changing anything, but simply analysing the situation to gain knowledge of the events.
Where would you go, and what would you do?