My main lounge use is on LAX-FRA-BCN, so a bit limited.
1. TG lounge in HK
2. LH lounge on upper A level in FRA (good food every now and then)
3. AC MLL in one of the satellites at YYZ (don't remember which one)
4. UA RCC at LAX (i like the layout, but there's no food or service)
5. JK lounge in BCN (ratty furniture, but they have Spanish Fanta)