In a previous life I managed the real estate assets for a US Company with a presence in Europe and the UK. I made 6 trips to London while putting up a new distribution center and sales office, and always stayed in Wimbledon. I guess I must have a defective palette, because I could never embrace the traditional English food or the Pub Grub. Fish & Chips was fine, but for a decent meal I would take the Tube to London and eat at the many International restaurants like Italian, Turkish, Thai, etc.. The Hard Rock Cafe was also pretty good.
You can find just about anything you want, foodwise, in London and the surrounding 'burbs.
Now if you ever get to Cologne, Germany, don't miss out on Cooper's Brauhaus for a great meal and sample their Kölsch beer. It's sooooooo smoooooooooth!