If you're talking about a Centrifugal Juicer, like the Jack LaLanne, then they're all pretty difficult to clean. I have an Omega 4000 which I've grown accustomed to, like an old pair of shoes, so I don't mind cleaning it.
The easiest type of juicer to clean are the Single-Auger models, like the Samson 6 in 1, Omega 8003, Solo Star 2, and the Champion......WY