I think the nicest looking (although I haven't seen them in person) are the Proporta covers -
http://www.amazon.com/Proporta-Handm...8172762&sr=1-4
However, because I like the nightlight functionality for the PRS600 (reduces reflection) I tried the Sony cover with light and the m-edge with the e-luminator2. The latter was my preference hands down. The case is nicer, more sturdily made and more padded with better leather. The light is much brighter for the same size. Plus it comes in fun colours which are really nice in person as well as online (at least the red and the green are - haven't seen the others). The only negative in my mind is that I prefer the hinged functionality of the Sony covers to the corners straps used by M-edge and that is strictly an aesthetic complaint - functionality wise they are equivalent.
Mel