If size/width of stage is all you want, the Sylvanias do this best. Particularly the metal base W's if you can afford them. All of the Sylvanias with good reputations count this as a strength though.
If imaging/holography is also important there is really only one tube that does it all in my opinion: the black glass round plate Tung Sol. Most people would also mention the ECC32 here as well, assuming you can use it safely in your amp, but while it is a technically excellent sounding tube I never found it emotionally engaging in my setup which is just as important as the technicals. This is why the Marconi B65 hangs out in my OTL a lot lately. It isn't the best sounding tube from a technical standpoint, but it is the most emotionally pleasing one by far.
The best way to find your own priorities is to just taste test some tubes and then go back to what others have written and see how your impressions are lining up.
thank you Xcalibur255 for this helpful post ,... "black glass round plate Tung Sol" ..I have this one
but I really love this tube ..(can't get enough of this shorty-it's actually taller then TS)
Edited by spacequeen7 - 2/17/14 at 1:54pm