Is Bellevue Rendez-vous gone...?? When?? How?? I think I'm going to cry...
I second Chez Bruce (my favourite by far!), Trinity, Mien Tay, Kaosarn (the Thai on St John's Hill), Tokyo Retro on Abbeville Road, Commensal on Abbeville Road, Thali and Pickles (a great authentic Indian in front of Balham Station - also perfect for lunch, unlike many Indian places with heavier dishes).
I'm afraid I disagree on Numero Uno and am not a great fan although I'm there quite often as a friend who used to live here gets nostalgic and insists on going there every time she visits. I think they have a great atmosphere and lovely service but I find food average at best.