Benehana (not sure of spelling!) at Swiss Cottage is fab. But then so are those large restuarants in Greek Street and around Soho with duck drying in the windows. I've always been a bit worse for wear by the time I've got to those so I can't remember any names!
Benihana is Japanese. Mr Wing's in Old Brompton Road, near Earl's Court tube, is the best I've ever been to. They do the world's best crispy duck. It's a bit pricey though about �50 a head.