It very much depends on the individual. I prefer an almost, but not quite, solid state sound. Many prefer more rolled off highs and pronounced mids. Some favor a heavy bottom end. Tubes, to me at least, are a kind of expensive and overtly complicated tone control. You have to experiment a bit to find the sound you prefer, since they all add a bit of coloration in one way or another.So that means pretty all varieties are great.
Baldwin "Greenies"--Sylvania long plate 12AX7 branded Baldwin with green lettering. The orange, yellow and white Baldwin labelled tubes were RCA and Raytheon, and IMO, not as good. Nice smooth gain and very quiet background--love them in phono pres.