I’ve used a variety of feeders over the years but this is the style I’ve stuck with.
I picked up a large pile of PVC pipes through freecycle and made two feeders with slightly different sized pipes.
PVC is easy to cut so you can make them any height you want. There are caps on the bottom and I’ve seen some folks with outdoor versions like this put a cap on the top at night time.
They are easy to fill and easy to clean, they don’t take a lot of space and can be mounted anywhere. There is some spillage so I have a large tray at the base to catch the pellets. The tray is also where I put oyster shells.