A good local freight clearing agent (London)

Hi, for those of you who have had to ship your things from somewhere overseas (i.e. by ship): Do you have any good experience with a good quality local London clearing agent--i.e. the person/firm that would get all the clearance for goods arriving at London port to get into the UK? I hear it's a bad idea to pull someone off the web as the quality of services of clearing agents is highly variable! I would very much appreciate recommendations!

Thanks,
Mimi