I generally prefer to travel by train whenever possible. I think plane travelling these days has become a pain with all the security checks and not being able to take what I want on board. And plane travel is also often more expensive than train travel. And there are the environmental issues concerned with plane travel.
But when I dont have much time and am going to a destination at the other side of the world or if overland travel would involve travelling though countries that are not currently safe I prefer to fly.