Paris is a must do if it is romance you are looking for. A year or two ago Conde Nast rated the Jules Verne restaurant on top of the Eiffel Tower as the most romantic place you could spend Valentine's Day. If you go to Paris, you could spend several days there, then, take the high speed TGV to Nice for a few days on the french riviera. Nice is very nice, and very pleasant weather, which isn't always the case in Paris.