They are all in demand at the moment, tracked excavator, forward and rear tip dumpers, blades, graders, you name it, if I had the choice of only one over everything else, it would be tracked excavator, none of the others work without the excavators.....
However, it depends on where your heart is, what you looking at going into, some good money for blades on road work, good money for graders as well, but track exc not so good.
every man and his dog has track tickets, myself included, but it's my bread and butter work so I don't mind the input to keep them, where as my blade ticket run