Best color CRT?

[heathkit tv]

Sorry if this has already been hashed out but I'm curious as to what most feel to be the best color tube. Guess it pretty much boils down to a discussion between RCA/Zenith and Sony.

When I say "best" I mean best picture and not necessarily most durable. Obviously the chassis directly impacts the quality of the picture, but realizing that many sets have had different brand tubes installed in them (except for Trinitrons) I was hoping that others could offer their opinions on this. What sayeth youse?