Kun's and Sidious' are quite remarkable in terms of design, IMO. I also liked the design of Luke/Obi-Wan's lightsabers, though they are more standard (of course). I suppose I've liked all curved-hilt lightsabers, just owing to the fact that I generally liked the characters who owned such weapons - Baras is a notable example because I like the way his hilt has a rancor tooth integrated into it.