Au Lac for Vietnamese, Firezza for pizza, Tiffin Tin for Indian, Tootoomoo for pan Asian. Au Lac doesn't take cards but will take cheques if you have no cash. Have fun!
love pan dan leaf on crouch hill for thai: http://www.pandanleafthai.co.uk/
Jashan on Turnpike lane is a rather special Indian restaurant. Not your usual menu. Indika on Green Lanes is also very good.
Thanks to everyone for all their recommendations....we've actually tried Firezza and Indika based on your comments and both were great. Really looking forward to testing our the others soon.