I'm usually as you can't get the stuff on tap up here, but I'm just bought a couple of bottles of "Master Brew" which I havent tried before and its very unsatisfactory. Back to the Spitfire....
Harveys do some great bottled beers, I like their Christmas Ale, Bonfire Boy and even their Nut Brown. They also do one off brews for special occasions like when Lewes had it's big flood.
Shepherd Neame is the oldest brewery in the country, they do some nice draught brews. My favourite brew remains a nice pint of Abbot though from Greene King, nice and bitter, hoppy and with a long finish.