If I think of memorable lounges, Conrad Tokyo has one, Conrad London used to have one, as well as London Hilton (at Park Lane). Hilton Bankside, Tower Bridge, and Canary Wharf were ok when I still traveled there on monthly basis. Hilton Shiphool remains nice. As well as Helsinki Airport and Strand. Hilton Joburg had a nice lounge and also very nice downstairs and pool bars. But Hilton Capetown (RIP) not did so. It so much depends on what You expect. Getting boozed or avoiding dinner cost...