Interesting lists! I wonder how many members have unknowingly crossed paths? It's fun to try to remember. My list is a bit of a cheat though because a lot of the places we stayed for over a week were for work.
UK: Machynlleth and Swansea in Wales, Edinburgh (many times), London (often), Oxford, Lowestoft, Hindon (Wiltshire)
Ireland: Clashmore (Co. Waterford) Youghal (Co. Cork) Dublin
Spain: Granada, Barcelona, Madrid, Pontevedra, Bilbao, Fuengirola, Alicante, Palma de Mallorca, Ciutadella (Menorca), Ibiza and some flyspeck village near Burgos that I can't remember for good reason
Italy: Rome, Venice, Naples, Florence, Milan, Arezzo, Lucca, Perugia, Arrone (Umbria), Siracusa, Catania, Palermo, Cagliari, Alghero, Ponza
France: Paris, Azay-le-Rideau, Menerbes (Provence), Ajaccio, Bastia, Marseille, Nice, Carnac, Avignon, Fumel, Caillac, Prayssac, Pomerede, Floressas and Puy l'Evêque (last 5 in the Lot)
Greece: Athens, Ikaria (at least every other year-my dad's from there), Thessaloniki, Corfu, Kefalonia, Chania, Heraklion, Rhodes, Akrata (Peloponnese), Nauplion, Santorini, Lesvos, Evia, Vilia Attikis (Attica)
also Valletta (Malta), Istanbul, Izmir, Kusadasi, Bodrum (Turkey) and Amsterdam