I too hunted for good karate clubs but they are few and far between.
In my opinion, this club looks like the best bet for Shotokan : http://www.seikukan-karate.ch
It is quite a trek however to get there.
I may look to offer a short training course here in Pfaeffikon SZ.
It would depend on how many wish to try of course and finding a suitable dojo (hall) to rent. I'm no Bruce Lee or Enoeda but have trained with some great Karateka over the years. It would certainly give people a tremendous foundation for what traditional karate (JKA Shotokan) is all about.
Let's see what the future brings! :-)