Thomas Cycles- good stock, happy to let you test, Ipswich. Good service IME.
Elmys- good stock, happy to let you test, female manager, Ipswich. Great service IME.
Pedal Power- perhaps not quite the stock of the others, don’t know about tests but would have thought it’s ok, Ipswich. good rep.
Lifecycles- lots of top end stuff, good rep. Bildeston.
Halfords- bargain boardmans, no test, inconsistent service.
Paul’s Dereham- online bargains if you know what you want.
If your just getting into the sport/hobby I would add extra value to service over getting an upgraded widget on the bike.