Our pit has a mobile island made out of two toolchests, and a spot for the robot on top. We also have a back area made of shelves. This is (along with our battery cart) all we have in our pit, which gives us a place to store tools (toolchest), robot (top of carts), storage for hardware (shelves), a place for immobile tools (shelf), extra workspace (shelf), and a place to store coats, etc (top of shelf). On top of these shelves, we have a bank of TVs that display a powerpoint.
This design is very clean, and gives us enough room to work and room to store all our stuff without feeling cramped. I can't really stress how good this feels - you have space to move around people without it becoming awkward! It's also quick to set up and easy to transport.
For five most important things, I would put toolchest-island first. It's nice to have a work surface that also stores your tools.
Second, our bandsaw. We had tons of people use it during 10,000 Lakes (we joked about setting up a fundraiser by charging 1$ for using the bandsaw), and we couldn't have fixed a few essential parts without it.
Third, our powerpoint TVs. TBH, it looks nice. We had a good number of compliments on these last season.
Fourth, (though this is kind of cheating) the shelving. Work surface and storage.
Fifth, our battery cart. It's essential for a robotics team (so I would put it higher), but ours is up for a bit of a redesign, as it's a bit clunky and space-inefficient.
Here are some pics. In the second one you can see some coats up top.