I had a Thule one which you hang bikes off, but found it very fiddly to fit three bikes on, and they could rub against each other & scratch the paint etc. Positives for it were low cost, easy storage, light weight, it hinged down to allow access to the boot, and it fitted easily in the boot when we arrived at our destination & got the bikes off. It was a Thule Hang-on 972 I think.
We now have a Buzzracks Quattro 4 bike model which the bikes stand up on.
It is an absolute beast, takes up more space in the garage & is pretty heavy to lift on & off the car, but it is very solid and the bikes have plenty of space. It still hinges down to allow boot access and it is much easier to get the bikes on & off. The rack locks to the towball and each bike clamp has a lock as well, all locks the same key.