Excavator and loader but the loader could be a good sized skid loader not a big wheel loader. I use my skid and excavator the most. A dozer you have to have if you have dozer work to do, just to time consuming to use a excavator but can be done. All this proves is that it is very hard to get into site work with just 2 machines, I found this out real fast and had to buy
dump truck
trailer
skid steer
excavator
dozer
roller
and still could use a backhoe, nicer dump truck, bigger dozer, bigger excavator, smaller excavator, wheel loader, lowboy, dump trailer, another skid steer, screen plant, hoe pac, trench box, big pole barn for all this to sleep in, on and on and on.