Best BA lounge I've been in: LGW Galleries (only silver so never been in T3 CX F / CCR / GF). Still better than LHR T5B in my opinion.
Best overall lounge I've been in: DOH Al-Safwa
Worst overall lounge I've been in: Tie between TXL AirportClub and STR Elli Beinhorn. The latter doesn't even have any windows and only had one bottle of wine in the whole lounge.