Are you talking about just a broker or a broker and combined trading platform??
Most traders these days seem happy with MT4, MT5, Ninja Trader, Trade Station or IG. Being in the UK I am not sure but I believe that IG or Quando seem to be the popular brokers.
I am in Australia and I use FXCM and have zero problem with them when it comes to withdrawing money. I don’t use their platform or any of the above mentioned platforms. I use a platform call Track N Trade. However you have to buy the licence to use that platform. Track N Trade is a great visual and practical platform and I use it mainly because I trade futures through Gain Capital on the USA futures market.
Hope that helps.