We've done some pretty good ones over the past few years ... ones that stick in my mind are:
Zombie Prep Merit Badge ... twists on First Aid, "Capture the Cure" game (glowing nalgenes filled with glow stick juice, held at night), "Dead Worm" (Gummy Worm) cooking contest, Zombies (commissioners) on the loose
Pumpkin Chunkin ... many small pumpkins lost their lives that day ... trebuchet's only, size and weight restrictions enforced, shooting sports director supervising the "range". Pumpkin carving contest. Pie cooking contest. Pie eating contest. Pies as prizes ... they look at you weird at Costco if you walk in and buy 20 pumpkin pies.
Are You Tougher Than Your Scoutmaster ... Patrol vs SM or ASM contests at each station. Jr ASM Eagle Scouts competed against their old Patrols (Jr ASMs cleaned up). I was SM then, and I smoked my patrol at cooking an egg using nothing except what I carried, and no matches or liquid/gas fuel (everyone had a list of equipment to bring to the contest)
Shooting Sports ... the person who was going to plan the camporee backed out very late, so we gathered our shooting sports folks, went to our camp and opened all of the shooting ranges (tomahawks to shotguns)
Historic ships ... held next to a museum with Revolutionary War boats (oared) and underwater drones. Scouts got to check out the museum (including the drone, and the blacksmith shop) and go in groups of about 10 to row a very, very large rowboat
Our unit went to the STEM statewide camporee in NH at the NASCAR track. Very cool, very well organized. Too few porta-lets, but having grey water containers and 55 gallon drums for ashes was a great idea
Our statewide in VT was a Civil War reenactment (I missed it with a conflict, but heard it was awesome)
The NH event had food stands and stuff on sale. We've never had that at any of our camporees. Once ... once ... our Camp Auxiliary sold hot chocolate and hot dogs.
We aren't usually merit badge focused. Generally, ours are Scout Skills (Trail to First Class) focused (with some exceptions ... archaeology MB at the maritime museum)
Sometimes our camporees are very rigid (you shall be at event station X at precisely 10:20 am), and sometimes (like the shooting sports event) we just open up activities and let the patrols roam.
Our upcoming camporee is being held at a fairground concurrent with a home show. We're going to have a bunch of exhibits set up along the main traffic route for recruiting (monkey bridges, fires, cooking)