Try Restaurante Andalucia in Ferring quality Spanish restaurant
'Food' is quite good, as is The River Kwai
Limings is good for Mexican style food.
Obviously you have Ask and Pizza Express for your usual Italian stuff, you know what to expect.
There's a tiny italian place down next to the Guildbourne centre, really family run, good atmosphere, used to go there for amazing sandwiches. Will post the name when I can remember it.
Was going to do Thai Kitchen in Littlehampton but Spices or Lemongrass sound good! Can't decide where though - argh!