Not counting the CX-operated lounges, which lounge is the worst across the network? Which is the best?

The DPS lounge (currently under renovation) is probably the worst I've been to in recent memory. It has a terrible design, not enough seating, and almost no food on offer. ORD is a close second with similar problems.

Aspire First at ZRH is a nice surprise with sit-down dining and is normally quiet.