The Plough is a bar and kitchen near Clapham Junction Station (the upstairs exit with the high platform numbers). It does good food all week and the Sunday roasts are particularly good. It has a nice selection of wines and the Guinness is good too.
My favourite thing about it is the Sunday evening quiz. It starts at 7.30 and finishes by 9.30 so easy to get home after. There is a maximum of 6 per team and although the venue is quite big, tables become quite hard to find if you arrive after 7.15.