You've probably been and come back by now but couldn't resist posting! Paris is lovely and always worth seeing. If i had to choose - in some weird on pain of death type scenario - would have to choose Paris. But Lille is lovely too, has a charm all its own. I've been there a couple of times. The centre is compact enough to explore on foot. Sunday morning market near the old Hospital. You can also visit General de Gaulle's childhood home - there are audio guides available in various langauges including English. In a near by town, Roubaix, there is an art gallery in an old municpal swimming pool. The building is wroth seeing for its self! You can get there on teh tram and the underground train. Then there is the beer, moules frites and waffle things. yes, I feel the need to return to Lille!