I've had a good think about this, and on the whole it's easier to name the not-so-good ones. Hello Hamburg and Bordeaux (third party lounges). When in Rome, don't go to lounges.

However in the spirit of the question, I'd suggest IB in Madrid, IB in Barcelona, CX in CDG, Munich, Brussels (bit relative), Nice, Zurich, Basle (these are third party lounges), a case can be made for MXP if Mummy and Daddy are on reception; also Linate.

But I'm afraid I've got a terrible soft spot for TXL, and I realy don't know why. It's falling apart, well past its "use by" date, worn out, slightly worrying floor stains, dodgy electrics, has the mini egg mountain and huge slabs of Teutonic cake. But the staff are charming and I guess it's a pair of old slippers really, bit sad to see it go.