The couple in the food court at Victoria Station, who carefully weighed themselves (sans shoes, of course) with a set of bathroom scales they clearly carried along for the purpose, before getting down and dirty with a Big Mac.
The singer downstairs at the foot of the escalator at Piccadilly Circus tube, using a road cone with the end chopped out as a voice amplifier (worked well, too).
The sax player a little further along in the Bakerloo tube, playing along to a recorded drum track. He was Asian, wearing a plastic red nose.
The Kiwi music played non-stop at the Wicked Wolf pub (just around the corner from Kypera in Charterhouse Street), chosen by (I asked) the Irish barman, named (what else?) Paddy.