In my case they all suck because I am assigned to a crew whose sole duty it is to load and unload the bellies of UPS aircraft. It is hard to choose an aircraft I like to work on the most. The easiest aircraft to work on are probably the Shorts 330 and 360 feeder aircraft we get at SDF
every night. I can actually stand up straight in those aircraft. As far as the UPS fleet, I like the 757 the most. The belly doors are easy to open, the belly is quite spacious, and the nets are the easiest to put up and take down. I like the DC-8 the least. The doors can be hard to open and close, especially on bellies 2 and 4. Those doors require a bit of technique to open. After you spin the lever, you have to push in the top of the door until there is a space to grab it at the bottom. You then have to pick the door up and lift it until it folds into and locks into the ceiling of the belly. Closing it is worse, since the door is heavy, and you have to control the door's fall into place. If you aren't careful and don't brace the door with your hand, it can fall and hit you square in the head. I don't wanna know how bad that would hurt.
I also like loading the MD
-11s. UPS SOP requires that the rear belly and cargo hold be loaded last to avoid tail tipping. When our crew is assigned an airplane to load, we sometimes get there before the "topside" crew (that's what we call crews who load/unload the main deck of the aircraft). This means we can crawl up into the belly and take a short catnap while we wait for the rest of the plane to be loaded.