The most interesting Rickenbackers are the hollowbody models. In particular, the 1958 to pre-June 1964 Capri models with the old style (squared edge) body shape, "stove" or "TV" knobs, and gold pickguard are the most interesting and rare. The export Rose Morris models with the 'f' hole are also rare and very collectible.
What I have in my collection is a 1960 Rickenbacker 365 Capri. This is a very rare guitar in very nice shape. It sounds incredible. The sustain and resonance is just fantastic. My view is that this is due to the body construction as this "OS" (old style) body for models made between 1958 and 1960 were thicker (2 1/2") as opposed to models made in 1961 and after which were thinner (1 1/2"). This 1960 model also comes with the Stereo "Rick-O-Sound".