Myself and my better half often have a day trip to Le Touquet (via Speedferries Supertickets).
Thursday and Saturday is market day and excellent for cheese, fish, meat and handbags (apparently).
Whilst we haven't stopped overnight, we have had a very leisurely lunch at the restaurant
http://www.leparisplage.com/ on the 'high street' along from the market place and post office.
I recall they serve Leffe (but not tartiflete)

Recommended
- you could also take your bucket and spade and paddle in La Manche.