Unless things have changed, add:
Berlin - Tegel
Warsaw
Hong Kong
Incheon
Los Angeles (LAX) - not strictly a terrance, but the Theme Building has I believe recently reopened.
I should add that there are still plenty of airports that have viewing areas away from the terminal, such as Manchester. Several major US airports have such facilities - I was at Charlotte last year, and it probably has one of the best located "park and view" areas around!