I am currently spending most weeks in Paris with work so spend many a day at CDG 6 excellent spotting, lots of variety, and most of the spotters i see here that are brits are usually daytrippers with EZY and alike.
CDG has several excellent viewing areas, the best of which is undoubtidly where thesaint has pointed out where with good binocs you can read off all the movements. Le Bourget is about 3-4 miles away which is where i am working out of, and is the biz-jet capital of europe. Anything from Beech 200 props to B777s/747s/707s/A340s and anything in between (esp 727s!). Well worth pooping down here for an hour on bus 350. Also Orly is to the south of the city and can be reached by train direct from CDG in under an hour. Hope its of use – i am certainly making the most of mly time here!!!