Hard to go past the Fernseh KCU-40B - three tube Plumbicon. However I am biased ;-)
A KCU is the first camera I operated live-to-air. Way back I volunteered for a shift on a local telethon type show. As a technician I'd done camera control for three KCUs on many an occasion but this was the first time the producer would let me loose on the camera itself. Quite a buzz when the little red light in the viewfinder first came on
Later on I bought three KCU chains ex another station here in Perth. I keep one in operating order, the others as spares :-)
Second vote goes to the Marconi Mk VII. 120 Kg [just camera head and lens] must have made for beautiful moving shots? Interesting FOUR tube system, with an optical 'switch' to direct all the incoming light to just the Y tube for extra sensitivity in fading light. I'm told it was common for English soccer matches to go live to air in colour for the first half, then switch to mono for the later-afternoon half!