Swiss
Having just flow Swiss in F, I heartily recommend it. You will need access to Expertflyer to see availability as LX doesn't show up on the ANA tool. If you PM me with some dates, I will be happy to take a look.
LX availability to NRT in F is pretty good.
LX short-haul C is as good as intra-Europe short haul gets in my view. Finally, whilst I haven't been to the LH FCT in Frankfurt, I was super impressed with the LX F lounge.
(My LX LHR-ZRH-JFK // SQ/LH JFK-FRA-LHR trip report is almost ready to post - more of the above to come)