I've lived in London for the last 22 years and there is no Uncle Sams up here, so I have tried many, many burgers. Whilst out of touch with Brighton's current selection, most of the chains and gourmet burgers are found up here in the North. Even had a Wimpy in Worthing last year!
Can't be bothered to read through the thread. The answer is and has been since the mid 70s - Uncle Sams. Also best burger in Worthing, Shoreham and anywhere else in the country they have a branch. Unfortunately in Walthamstow I have to rely on 5 Guys.