+1 for le touquet, some parts are like Cannes (big hotels, casinos etc but can be a bit snooty, maybe my bermuda shorts and kiss me-quik-hat were not appropriate apparel) whilst the market area offers a bit more cafe/village lifestyle.
good for golf, horse riding, tennis and windsurfing.
It can be a bit quiet off season (the bigger places seem to shut up shop in the autumn and dont wake up till easter) but this time of year should be bustling