Read about the various tours on Top Questions, but am still unsure about which bus tour would be the best to see the city (possibly a double decker). We are only in the city for 2-1/2 day, but am considering doing a bus tour for an overview of the city, preferably with one that stops at the GGB. Dylan's seems to be popular. I would like an opinion on the best one to use, and any outstanding tour guides. Thanks for your help.