I like all.. and love trains.. Generally speaking I prefer car, especially if someone else is driving. Plane means I can go somewhere further away.. boat means water and I love water... bus means someone else is driving and I can just look out the window and daydream
It doesn't sink and sharks can't eat me if I get out like in a boat. If my engine has problems I just pull over rather than crash into the side of a mountain like in an airplane. I don't have to follow the railroad either. I go where I want to on land.
I like driving because I like to have control of my vehicle.
Ideally, train, or bus if it's a direct route, or some combination of these. If that would mean a very long and expensive journey, the destination has no rail connection or it would take more than one change, I may drive instead. The last time I went to a foreign country was Iceland last summer, I flew there because there is no realistic alternative, but if I am going to continental Europe I will at least loom at the option of rail even if it means an extra stop-over. The only two times I have been to Ireland, I chose boat.