Both, but if I had to pick just one of the two it would be truggy. For several reasons. Truggies take less effort to drive competitively(in other words they are easier to drive). They handle rough tracks better, and to me it's just more fun being able to throw the truck around and not get out of shape. On the same note however the buggy will teach you more, and if you can master that truggies are easy in comparison. Buggies are the premier class of offroad, they are by far the most competitive class, which can be a positive or a negative depending on what you are looking for in a racing experience.
