I’m a big fan of the Tube here in London, but I took a bus last night for the first time and I recommend the experience. You get a much better sense of the city than you do burrowing underground from place to place. If you can, get on one of the double decker ones (they also have the long accordian buses here, which I think are newish) and sit on the upper deck in the front. With the huge windshield in front of you (and not much else), you feel a little like you’re floating around the city. Quite fun.