I'd avoid LHR and BRU for multiple reasons.
FRA/MUC/ZRH are all good options.

LIS has a good lounge but long lines at non-Schengen passport control at arrivals.

LIS/ZRH/FRA are close enough to the city if you want to make the trip for a quick walk.

I'd avoid any Italian cities.

VIE is ok.

CPH/ARN had decent lounges pre-COVID, especially for breakfast.